ABSTRACT. This paper studies the performance of a practical ground source heat pump (GSHP) system by real-time monitoring data. The GSHP system, which is installed in an office building of Shaoxing (29.42°N, 120.16°E), China, is real-time monitored from Nov. 2012 to Mar. 2015. Data Mining (DM) technology is applied to clean the monitoring data. The performance of the GSHP system is evaluated by clean data. The results show that the application effectiveness of this system is unsatisfied because of the persistently low load ratio (LR) and COP (EER, in summer). The condition of indoor temperature and relative humidity (RH) can just basically conform to the uses' requirements both in winter and in summer. The percentage of average LR in each mode over 60% is unsatisfactory. The soil temperature remained relatively constant throughout the monitoring period. The average COP2 is 3.28 in winter mode, with the average COPsys is 1.97. And the average EER2 is 3.56 in mode S1 and the average EERsys is 2.23. In mode S2, The average EER1 and EER2 are 3.40 and 3.68, respectively, and the average EERsys is 2.39. Low LR and irrational energy consumption proportion structure are two main reasons for the relatively low COP (EER).

ABSTRACT. Introduction Energy saving potential of the air-to-air heat pumps has been argued ever since they were introduced to the Finnish national building regulations with fixed annual net heat production of 1000 kWh in new buildings. In the energy labelling legislation the granted annual net heat production is higher ranging from 1000 kWh to 6000 kWh depending on the building year. The regulations are under renewing process and this study gives background information for that but the results are also useful for the designers, heat pump dealers and common occupants on the real energy and economical savings that can be realized with air-to-air heat pumps.

Methods Air-to-air heat pumps have been studied in the Finnish climates (Helsinki and Sodankylä) in order to clarify their real energy saving potential as well as in old, present and tomorrows nearly zero energy detached houses. IDA-ICE software has been used in the simulations and the model is verified and tuned by the measured data published by Scanoffice (Finland) and Energimyndigheten (Sweden). Two different building layouts have been used in the simulations representing typical Finnish old and new building types. The old house is one-storey building where air-to-air heat pump is located in rather open space consisting of living room and kitchen. The new building type is two-storeyed where heat pump is located either in the living room downstairs or both downstairs and upstairs in the hallway.

Results and Discussion The paper will present net heat production of the air-to-air heat pumps in relation to heating energy demand of the building and corresponding SCOP values and savings of purchased energy with different operation set point temperatures (21,5 – 24 °C) of the heat pump. The results show also how the heat spreads around the building. It was find out that the air-to-air heat pump model of the IDA-ICE is a bit tricky to adjust for specific heat pump because of so many parameters to be tuned. Also the lack of measured data (heating power and COP) especially at part load conditions, which is often the main operation range, complicates the tuning of the model and increases the margin of error of the results.

Conclusions The main result of the study is a proposal for the defining of the energy savings of the air-to-air heat pumps in regulations. Simulation results shows that the net heat production is not sensitive on the heating power characteristics of the heat pump in the new and nearly zero energy buildings. In the old building the low heating capacity of the heat hump may limit the net heat production during the lowest outdoor air temperature. The seasonal co-efficient of performance (SCOP) depends clearly on the characteristic but also on the part load conditions. This means that in buildings with lower heating demand the SCOP is better than in buildings with high heating demand with the same heat pump.

ABSTRACT. A micro - exhaust air heat pump in combination with a mechanical ventilation system with heat recovery (MVHR) offers great potential for a cost effective heat supply for highly energy-efficient buildings. Particularly, for the renovation of multi-family houses, where central solutions are often not possible for various reasons, a decentralized MVHR with heat pump represents an appropriate solution for ventilation, heating (and cooling). A major advantage of such a compact system is the ability of façade integration: a space-saving and attractive solution can be achieved while the renovation can be accomplished with minimum disruption, which is one of the main objectives of the EU-project iNSPiRe, see e.g. Ochs et al. (2015). A challenge in the development of such a compact solution is maximizing the efficiency within the space limits and in the same time reducing noise emission to minimum. In addition, accessibility for maintenance and repair has to be guaranteed. A high efficiency can be achieved only through a combination of multiple optimization steps. This includes in addition to a very efficient air-to-air heat exchanger, a variable speed compressor, an optimized control for pre-heating (frost protection of the air-to-air heat) and post-heating (central or decentral auxiliary heater, such as e.g. bathroom radiator), as well as an optimized defrosting control of the evaporator. Pre-heating can contribute significantly to the total electricity consumption and can be reduced or even avoided by means of using an enthalpy exchanger. This article deals with a description of the concept of the micro - exhaust air heat pump as well as the discussion of the opportunities and challenges of optimization. Results of component, system and building simulations as well as measurement results are presented. Measurements include indoor laboratory measurements of the icing behavior, outdoor laboratory measurement results of the system efficiency in so-called PASSYS test cells as well as monitoring results of a demo building in Ludwigsburg (Germany). In the focus of this article is the discussion of defrost strategies such as control acc. to the (operating) time, by means of pressure difference, increased power consumption of fans or a predictive controller.

Ochs F., Siegele D., Dermentzis G., Feist W., Prefabricated Timber Frame Façade with Integrated Active Components for Minimal Invasive Renovations, 6th IBPC, Torino, Italy, 2015

ABSTRACT. The performance of heat pump heating systems crucially depends on the temperature lift during their operation. The temperature lift depends on the type of heat source and the heat sink but also on the implemented control and system integration. The seasonal performance is often projected on the basis of static performance tests in combination with seasonal boundary conditions.

A novel approach uses dynamic simulation methods and a Hardware-in-the-Loop (HiL) test bench. It allows to realistically consider system dynamics and influences of a system control. Whilst with dynamic simulations usually a whole year or a whole heating period is calculated within a manageable amount of time, on a HiL test bench shorter test periods are required.

Therefore, approaches for the determination of test days for the calculation of the seasonal performance of heat pump heating systems are investigated. The aim is to find weather conditions representative for the whole period of the operating time of the heat pump heating system. Different procedures are analyzed using a comprehensive simulation model consisting of the heat generation, the heat distribution system as well as the heat source and heat sink. Different types of heat pump systems are considered.

Subsequently, reference simulations are carried out for the complete period of operating time of the heat pump system. Thereafter, the test procedures are applied to the simulation model and simulated as well. The seasonal performance received from the reference and the test procedure’s simulations are compared. The deviation between the two simulations is used as an indicator for the suitability of the investigated test procedure.

Several methods of finding typical meteorological days are compared for different number of test days. Due to the thermal capacity of the building, heat is stored with time constants lager than the aimed test days. This energy shifting has to be coped with when executing the test procedures. Thus, in some of the investigated methods the main thermal capacities are simulated between the chosen test days. The results show that a clustering of relevant weather data by the k-medoid method yields in the smallest deviations of reference simulation and simulation of the test procedure. The procedure will soon be applied on HiL experiments.

ABSTRACT. To reduce building energy usage, novel heating-cooling solutions and building integrated renewable energy systems are required around the worldwide. Recently, the magnetic cooling system as an alternative method for the conventional cooling system is one of the promising approaches in terms of energy efficiency and environmental impact. Therefore, in this study, an experimental magnetic heating-cooling system has been designed and investigated. The current system has a permanent magnet pair, a magnetocaloric material, and a linear reciprocating system. In the system, 50 Gadolinium plates are used as magnetocaloric materials. Furthermore, temperature variations of Gadolinium for no fluid flow condition and different magnetization and demagnetization periods are investigated. It is obtained experimentally that the effective magnetization and demagnetization durations should not be less than 30 s.

ABSTRACT. Focus of this paper is to show the key facts for high efficient solar ice storage heat pump systems, their appropriate application area and furthermore includes the classification within solar heat pump system combinations. Background of the work presented here is the project SOFOWA on "solar heat, fotovoltaics and heat pump system combinations" which has been conducted as one Swiss national contribution in the framework of the IEA SHC Task44 / HPP Annex 38 "Solar and Heat Pump Systems". Starting point had been a system comparison of combinations between heat pumps and solar technology (solar heat and/or photovoltaics) by means of simulation. One result therein is that solar technology which improves the winter system performance is more useful in the sense of sustainable future heat supply systems than summerly solar thermal heat generation since herewith the efficiency of the heat generator providing the bigger amount of heat is improved. Especially for situations where only outside air, solar irradiation and the shallow ground are available as heat source for the heat pump, solar ice-storage heat pump systems show good system performance as well for buildings with low space heating energy demand (e.g. new buildings) as for buildings with higher space heating demand like older existing buildings. Simulation models for the solar-ice-storage system were developed and validated with field and laboratory measurements. The solar-ice-storage system has then been optimized for high effi-ciency and reduced system expenditure with four buildings of same size but different insulation quality. Heat pump systems with thermal capacities of 6, 8, 10 and 13 kW and solar absorbers between 10 m2 and 30 m2 show seasonal performance factors SPFbSt between 3.7 and 4.5. The convective heat transfer rate of the solar absorber is of key importance if used as heat source for the heat pump. A reduced convective heat transfer due to lower wind speed or disadvantaged design of the absorber reduces the seasonal performance by 6.5% to 11% and shows the biggest influence on the seasonal performance as long as there is no demand for direct electric backup. The yearlong availability of the heat pump as heat generator and hence avoidance of need for direct electric backup is assured by the latent heat gains in the ice-storage to secure the minimum heat pump inlet temperature in combination with ground heat gains in coldest winter month. Further improvement of the system performance is possible with PVT absorbers as heat source for the heat pump in the sense of generating more surplus electrical energy that is available for other appliances as long as the high convective heat gains of the existing solar absorber can also be kept. Key facts for high efficient solar ice storage heat pump systems are first of all a high convective heat transfer rate of the solar absorber, secondly the latent water to ice heat gains and last but not least ground heat gains in the coldest winter month to assure the availability of the ice storage as heat source.

ABSTRACT. A GSHP system which includes 2 heat pump units and 50 boreholes application in CABR Nearly Zero Energy Building was introduced in this paper. System operation in a cooling and a heating period was analyzed based on measurement data, including ground-side water temperature and flow rate, chilled water temperature and flow rate, heat release amount of both ground side and the GSHP units, and system contribution to the Nearly Zero Energy Building was discussed. It is found that water temperature of ground tube works at about 23-28℃ and 20-26℃ respectively in summer season, about 1℃ temperature variation happens in one day operation and around 4℃ inlet and outlet water temperature difference,. In winter season, ground side inlet and outlet water temperature works at 16℃ to 12℃, ground water temperature decreased from 16℃ to 14℃ after 2 month system operation, 2℃ temperature variation happens. As much as 19000kWh cold amount was supplied to the building GSHP 1 units, and system provide 4300kWh cold for the building, and the GSHP unit contributes 54.5% of the building cooling load.

ABSTRACT. The paper is a synthesis of a topical bibliography with theoretical, experimental and applied results;

Complex research program was based on analysis of data recorded by DDC for a period of more than two years, as the one in, Bucharest Romania;

Detailed geotechnical study at both regional and local levels favored an efficient design of the entire system, cold and warm requirement is covered by the minimum monthly costs, much lower than what would have been required of a classical system;

Maintenance equipment is easy and can be done for most situations via the DDC’s, and moreover, the complex automation optimizes these systems, getting significant energy savings.

In the case of the geoheat exchanger with boreholes with a single circuit, after the comparison between simulated data with software EED and recorded data it was shown that the average temperature values for carrier fluid are comparable allowing validation of the results.

The main problem was to prove that this new type of GSC will not disturb, energy wise, the crossed geological formations.

Finding a viable solution that is more efficient than the solution with vertical boreholes, closed, mounted in parallel with a single circuit;

For greater efficiency hybridization system is a solution that deserves to be carefully analyzed

ABSTRACT. Application of Thermoeconomic in the diagnosis of power plants allows the localization and quantification of an abnormal operation, which can cause significant increase in consumption or even unacceptable shutdowns. Accordingly, the early detection of these anomalies may prevent possible failures and make savings in both maintenance and energy consumption.

Thermoeconomics has not been widely used in the field of thermal installations in buildings, even less its diagnosis application. This communication contains the results of the implementation of Thermoeconomics diagnosis in a micro-cogeneration facility for DHW, consisting of a microcogeneration engine, a condensing boiler and an accumulation tank.

To assess the malfunctions and dysfunctions in a facility in which demand varies over time, virtual testing analysis path has been chosen. This is done through a dynamic simulation software of buildings (Trnsys). For this purpose, a common reference state and various operating conditions have been defined. These operation modes include different types of disturbances; first anomalies are introduced one by one and then several of them are analyzed simultaneously.

Once the productive structure of the system has been determined in its FPR representation, a thermoeconomic study for a specific situation has been performed. This analysis enables the obtainment, among other results, of the exergetic unit cost of the fuel, waste and product of each subgroup. Regarding the reference installation as the comparative base, the endogenous and exogenous effects a malfunction creates along the entire energy chain have been investigated. For the anomaly case, an analysis of the results has been elaborated and conclusions have been obtained.

ABSTRACT. Deep renovation of apartment buildings in a cold climate requires ventilation heat recovery, while supply and exhaust ventilation with heat recovery and exhaust air heat pump are the two most commonly used solutions. Supply and exhaust ventilation distributes heating need evenly throughout the year. Exhaust air heat pump on the other hand produces heat for domestic heat water during the summer and also covers heating needs in spring and autumn. Therefore the heat pump solution minimizes delivered district heat during warm periods, which increases heating district losses proportion in the heat produced in the plant. In addition some exhaust air heat pump connection schemes increase district heat return temperature, which reduce the efficiency of heat plants e.g. in case of combined heat and power production. The purpose of this study was to compare the delivered district heat profiles of a typical retrofitted apartment building with the two ventilation heat recovery systems and to study the return temperatures of the heat substation with three different exhaust air heat pump connection principles. We modelled an apartment building to determine hourly power and supply/return temperatures of the radiator heating system and simulated the heat substation performance in various cases. The generated profiles confirmed that an apartment building with supply and exhaust ventilation distributes the delivered heat more evenly throughout the year. Highest exhaust air heat pump efficiency was achieved when both its pipes were connected to the return pipe of the heating system, however the connection principle increased district heating return temperature significantly. When the supply pipe from the heat pump was connected to the supply side of the heating system and return pipe to the return side of heating system, the heat pump coefficient of performance decreased slightly, however the return temperature of district heating was reduced remarkably. The connection principle, when both heat pump connections were joined with the supply side of the heating system, decreased heat pump potential while the effect on district heating network temperatures was insignificant. Based on the results we suggest using supply and exhaust ventilation with heat recovery, but in case of exhaust air heat pump, its supply water should by-pass the district heating heat exchangers.

ABSTRACT. The mandatory provisions about the use of renewable energy introduced by the Italian decree D. lgs 28/2011 and by the European directive 2009/28/CE greatly increase the requirement to cover the primary energy consumption using renewable energy sources. In this respect, the vapor-compression heat pumps coupled with PV panels are a promising technology and, consequently, they are increasingly used for residential heating applications. This HVAC solution is made possible by the adoption of low temperature heating terminals (e.g. radiant panels) and by the better insulation of the envelope in new (and refurbished) buildings. The overall performance of the heat pump along a heating season should take into account the specific applications of the unit itself. The actual seasonal coefficient of performance (SCOP) is often different from the one provided in manufacturer's data and from the SCOP calculated as in the European Standard EN 14825. With a dynamic simulation program, such as Trnsys, it is possible to perform a better evaluation of the seasonal performance of Air Source Heat Pumps (ASHPs), which is strongly dependent on operating temperatures (of source and sink) and on the load. The available Trnsys libraries (Types) are capable to model only air-source heat-pumps with fixed speed compressor. Hence, a new model of variable refrigerant flow (VFR) heat pump has been created, modifying an existing “Type” (Type 941 by J. Thornton, 2005). Four working modes were identified in connection with the value of capacity ratio (CR): 1. HP working at nominal (maximum) speed; 2. HP working part load but with COP as declared in manufacturer's data; 3. HP working part load with reduced COP; 4. HP working in on/off mode because CR is below the modulating capacity limit. Simulations were carried out with a simplified configuration, modeling the heating load of an efficient building coupled with an ASHP in the typical climate conditions of Northern Italy (outdoor conditions were obtained from the test reference year of Trento, Northern Italy). The operating data in nominal conditions for different temperatures were obtained from manufacturer's data. The decrease of heat pump performance when working part load was modeled within the Type itself: such routine allows the user to define the trend of the curve describing the variation of the COP. Other important things that affect the seasonal performance, are the operation of the control system and the size (i.e. nominal capacity) of the device with respect to the heating demand. All these effects have been analyzed. The results show how the appropriate sizing of the heat pump, the proper design of the HVAC and the correct operation of the system itself (including the control strategy) should be taken into account in order to achieve the best performance.

ABSTRACT. The production of Domestic Hot Water (DHW) dominates the total energy demand. One of the main reasons for the high energy demand is that DHW is stored and distributed at temperatures above 55°C to mitigate the risk of infecting the DHW system with Legionella Pneumophila. At these temperatures, Legionella Pneumophila bacteria are effectively killed. For most of the applications of DHW, temperatures of only 30-40°C are required. This disparity (between 55 and 30-40°C) doubles the temperature difference between DHW system and environment and has a detrimental effect on the efficiency of DHW production units.

A simulation model is developed that allows to investigate the infection risk for Legionella Pneumophila in the design phase of a DHW system and to test the effectiveness of disinfection techniques on an infected system. By developing a simulation model that allows assessing the Legionella Pneumophila infection risk in dynamic conditions, HVAC designers will be able firstly to thoroughly assess the infection risk associated with their design and secondly to optimize the temperature regimes, choose better hydronic controls and reduce the energy demand for DHW production. Modeling a multi-family residential case study building pointed at considerable Legionella Pneumophila proliferation risk in the boiler vessels and dead pipe-ends.

In addition to the modelling work, a test rig is built which will serve to run experiments that will allow testing, validating and improving the simulation model. With this thermodynamically validated model, the Legionella Pneumophila infection risk of 5 to 10 often used DHW configurations from REHVA design guidelines for DHW systems will be assessed and new design guidelines for these configurations will be proposed based on an optimization study that looks at the trade-off between Legionella Pneumophila infection risk and energy efficiency.

ABSTRACT. 1. INTORODUCTION Recently, room load is on the decline caused by reduction of internal heat gain and improvements of thermal performance of building fabric. At the same time, it could be expected that outdoor air load become invariable. As a result, the proportion of outdoor air load for air conditioning would be greater. Thus, the measures how to handle outdoor air load might be one of most important issue of energy conservation. The purpose of this study is to suggest of performance prediction and a design strategy of earth-to-air heat exchanger, which is a measure reduce the outdoor air load. The feature of this study are as follows: ・The target building will be non-residential with medium-sized scale. ・The prediction of thermal performance for the systems would be estimated under the different design parameters. It would be required on the design procedure for this system that the prediction of outlet air temperature and the amount of heat exchange rate. In this paper, prediction method for outlet design air temperature and heat exchange rate is proposed. In addition, the design strategy by using proposal index derived is also proposed for design in the early design stages. And, proposal index is derived by using geometric building conditions. 2. METHODS First, the proposal index is derived by parameter study. In this parameter study, result of simulation using a numerical analysis model of the three-dimensional simple heat conduction is used. Next, the design strategy by using the proposal index will be developed by using installation areas of this system, building coverage ratio and a floor-area ratio. And, there are assumed that this system installed underground not under buildings without constraints of shape of the side and building.

3. RESILT As a result of parameter study, regression formulas are derived for the prediction of design outlet air temperature. And, the prediction procedures of design outlet air temperatures by using regression formulas is proposed. Moreover, the design strategy for this system is introduced by using the proposal index.

4. CONCLUSIONS Point of this paper is as follows: ・It can be expected that design outlet air temperature is predictable using the proposal index which is a unit value corresponding for tube of heat transfer area and introduced fresh air volume. ・the design strategy for this system in the early design stages developed by using the proposal index, installation areas of this system, building coverage ratio and a floor-area ratio.

ABSTRACT. This paper presents the description of the first stage of a project consisting on the monitoring of a newly installed borehole thermal energy storage (BTES) system that started to operate during the autumn of 2015. The BTES system is designed for approximately 4 GWh per year of heat injection and 3 GWh per year of heat extraction and will provide heating and cooling to a set of institutional facilities at Stockholm University, Sweden. The energy storage system consists of a set of 130 borehole heat exchangers, 230 meters deep. Strategic locations within the bore field have been selected to carry out the measurements. The monitoring system comprises temperature and energy flow meters. The temperature measurements are performed using a distributed temperature sensing set-up which allows to measure temperature along the depth of the boreholes, providing a large amount of data for the characterization of the thermal processes in the ground. During the upcoming years, the measured data will be utilized to evaluate and optimize the actual operational condition of the system, and to test the validity of assumptions made during the design phase. Moreover, the measured data will be utilized for validation of current bore field design methods and to have a better understanding of the thermal interaction between neighboring boreholes.

ABSTRACT. Introduction: The energy generation by fossil combustion is causing adverse effects such as global warming, climate change and acid rain. Renewable energy is thus playing an important role to replace fossil fuels and reduce the environmental problems. The solar energy harvested by photovoltaic (PV) technologies is recognized as sustainable and environmental friendly. Conventionally, large spatial area is required to install the PV systems. However, the building integration technologies adapt the system to the urban environment, which is effective in power generation and building envelop heat gain reduction according to the previous studies. The installation can be in the form of opaque building integrated PV (BIPV) on the vertical wall, semi-transparent BIPV on the vertical window and horizontal / titled PV on the roof-top.

Traditionally, the nominal efficiency of PV system is estimated under a reference sunlight of irradiance 1000W/m2, solar cell temperature of 25 degree C and air mass of 1.5. However, solar radiation and temperature vary with the weather, season and time of a day, which makes the standard test conditions rarely occur in practice. In this connection, it is necessary to evaluate and estimate the performance of PV system in operation according to field measurements.

Methodology: Efficiency of PV panels and its relevant parameters will be collected by field measurements. The artificial neural network (ANN) will be used to correlate the variation of PV efficiency with its relevant parameters which indicate the PV operation condition, including the temperature of PV panel, the solar radiation and the position of solar disc referring to the normal direction of PV panel. The panel temperature, on the other hand, will be forecast by readily available parameters that indicate the weather condition, including the air temperature, the mean radiant temperature, the relative humidity and the solar radiation. The correlations indicated by ANNs will be applied to determine the efficiency and year-round power output of horizontal, vertical, tilted and sun-tracking PV systems with the consideration of operation environment.

Expected Results: ANNs will be trained to predict the panel temperature and efficiency of PV panels in practice according to the parameters readily available in weather data. The year-round power generation of PV in different orientations and layouts will be estimated accordingly.

Discussion: The performance of different PV panel layout will be compared according to the life cycle energy, environmental and financial benefits. The implications will be discussed.

Expected Conclusions: The best layout of PV panel will be identified. The result will be important to the design of building integrated photovoltaic system.

Future work: The future work includes the co-simulation of the trained ANNs and building energy simulation software to determine the effect of building envelope heat gain reduction and the expected energy generation potential from the building integrated PV panels.

ABSTRACT. With the upcoming changing construction trends (higher insulation levels, tighter building envelopes etc.), the need for cooling is increasing, even in cold climate areas such as Scandinavia. One possible way to address this increasing demand is to use the nocturnal sky, which can be exploited as a heat sink for radiation heat exchange. This process is commonly known as night-time radiative cooling. Solar thermal panels can be used to exploit this phenomenon since they are already facing the sky, and using them at night increases their utilization factor. Experimental studies have been carried out using both one unglazed collector and three photovoltaic/thermal (PV/T) panels at the Technical University of Denmark (Lyngby, Denmark), in August 2014. The results in terms of cooling power and efficiency were reported previously (Pean et al. 2015); the present study focuses on the validation of a simulation model of those panels and the use of this model to evaluate the impact of different environmental parameters on the cooling output. The model has been built in TRNSYS, to simulate the two different types of panels. Simulations have been carried out taking as input the same weather conditions, inlet temperature and flow rates than the experiment previously described, so that the results could be compared. The difference between simulation and experimental results for the total cooling energy produced nightly proved to be in average 13% in the case of the unglazed collector, and 21% and in the case of the PV/T panels. Those results have been considered sufficiently accurate to utilize the model for further simulations. Several simulations are therefore being carried out to study the impact on the cooling output of different environmental parameters such as ambient air temperature, relative humidity, cloud cover, cloud height and wind speed. The parameters are varied within their respective range to evaluate their separate influence within these ranges. The results show that nocturnal radiative cooling highly depends on weather conditions. The cooling output is affected the most by the air temperature, which impacts both the radiative and convective heat losses. It was observed in this case that the cooling energy produced in one night is decreased by 75% when the temperature increases by 9°C; while the opposite change (temperature drop of 9°C) results in a +65% increase in the cooling output. Cloudiness, wind speed and relative humidity also affect the cooling output significantly. Unglazed collectors proved to be slightly more efficient for cooling applications than PV/Ts.

ABSTRACT. Abstract Current work presents a system with a tank and a heat pump that extracts the thermal power from a tank and supplies a consumer using the heating system. The thermal behavior of this system is dynamic from the point of view of the consumer that needs a different power each month (because of the climate change) and from the point of view of the variation of temperature inside the tank. It is presented the thermal modeling behavior of the system and the energetic requirements for the tank-heat pump system.

ABSTRACT. Pressurized evacuation stairwells provide safe escape routes to occupants and access to rescue crews in case of fire in a high-rise building. The air overpressure prevents smoke from entering the rescue staircase and firefighter elevator shafts. Pressure losses were measured in four stairwells to better understand aerodynamic flow resistance. Flow resistance was then determined from the measured pressure loss and air volume flow. The present paper reports a method to measure volume flow by the tracer gas method. We determined flow rates in the four staircases with high accuracy and certainty by using the tracer gas sulfur hexafluoride (SF6) combined with rapid infrared spectroscopy. We demonstrated that the constant-emission and pulsed-emission tracer gas methods are well suited for flow rate measurements under difficult flow conditions. The pulsed injection of tracer gas into the ventilation system requires an accurate mass flow controller. Uniform mixing of the tracer gas upstream of the measuring section is a key condition for reliable measuring results.

The measurement of air volume flow in pressurized evacuation stairwells is difficult because of geometrical constraints and aerodynamic complexities of the ventilation system. Flow rates in the four staircases could be determined with high accuracy and certainty by using the tracer gas sulfur hexafluoride (SF6) combined with rapid infrared spectroscopy. We used constant-emission and pulsed-emission tracer gas methods. The authors have applied these methods successfully in earlier experiments to measure the extract airflow rates of road tunnels. For the investigation in staircases with much smaller dimensions, the equipment and gas injection system had to be downscaled. Good measuring conditions were obtained by multipoint injection upstream, and multipoint gas sampling downstream of the fan for both methods and on all sites.

The results of the two measurement methods differ by less than 5%. This difference is caused by operating points that have not completely settled to stable equilibrium when the two tracer gas methods have been applied sequentially. An alternative method to determine flow rates in these four buildings by measuring air velocities in the duct cross section (grid method) would have involved excessive measurement uncertainty. The authors have prepared uncertainty budgets according to the ISO "Guide to the expression of uncertainty in measurement," GUM, for both tracer gas methods.

We demonstrated that the constant-emission and pulsed-emission tracer gas methods are well suited for flow rate measurements under difficult flow conditions. The downscaling of pulse generation was successfully accomplished. The pulsed injection of tracer gas into the ventilation system requires an accurate mass flow controller and a LabVIEW software application. Uniform mixing of the tracer gas upstream of the measuring section is a key condition for reliable measuring results. For future projects, the authors intend to replace sulfur hexafluoride (SF6) by nitrous oxide (N2O), or by 1,1-difluoroethane (DFE, C2H4F2).

ABSTRACT. The Danish government has targeted full reliance on renewable sources of energy for heating and electricity in buildings by 2035. Building renovations conserve energy and cancel the need for additional renewable supply. A Danish national action plan thus expects to reduce heating consumption in existing buildings by at least 35% before 2050. Renovations improve airtightness, which may then require mechanical ventilation with heat recovery. Consumers will likely demand flexible cost-effective solutions and secure knowledge of their proper implementation. Single-room ventilation provides simple installation, low fan power, and the potential for local heat recovery, but the topic has not been adequately researched. Prior simulations of single-room ventilation units in renovated Danish apartments showed that efficient uncoated rotary heat exchangers recovered excessive moisture from kitchens or bathrooms (i.e. wet rooms) and yielded a substantial mould risk. However, the single-room units in living rooms and bedrooms (i.e. dry rooms) recovered enough moisture to prevent dryness. Moisture production is more predictable and less varied in dry rooms, which reduces the risk of excessive moisture recovery. The results suggested a combined solution of single-room ventilation units that use recuperative heat exchangers in wet rooms and regenerative heat exchangers in dry rooms. This would optimally match the type of heat recovery and its related drying capacity to the ventilation needs of individual rooms. An additional benefit is that the units in wet rooms could drain to available plumbing, while the units in dry rooms may not require drainage due to moisture transfer. The present research used Matlab to simulate the impact of demand-control on a rotary heat exchanger in ‘dry rooms’ to achieve optimal indoor humidity. The rotary heat exchanger transferred condensation from the exhaust to the supply air in ‘dry rooms’, but this was controlled with variable flow rates and variable heat recovery (i.e. rotational speed of the heat exchanger) based on indoor humidity. These simulations demonstrated the efficacy of using demand-control to achieve optimal indoor humidity in ‘dry rooms’ and showed that this method was ineffective in kitchens and bathrooms. Instead, the combined solution achieved appropriate levels of indoor humidity in every room. The modelled ventilation units represented developed products and simulations represented a realistic scenario for a renovated Danish apartment.

ABSTRACT. The paper deals with design of the personalized ventilation system with possibility of air volume and temperature customization, using a Peltier module for heating and cooling of the supply air in a scale of few degrees. Ventilation and air treatment in the open space offices are always a really problematic issue. It’s almost impossible to make a comfortable environment for everyone in the room with central ventilation systems, because every people has specific needs and feelings. This problem occurs more intensively in the operations, where work requires high rate of focus, and low quality environment may cause a strong distraction. In these causes, the personal ventilation system comes with possibility of customization of the work place environment and provide a better comfort and focus on work. First part of the paper is focused on air supply system. Analyses the effectivity of air distribution, supply elements and impact on the work space environment. It mainly reviews the previous work on this issue, present personal ventilation system and diffusers, and the measurements using a thermal manikin. The result is effective layout of distribution element on specific workplace. Second part of the paper is mainly about the air treatment and customization. At first, it deals with calculation of the input power need for supply air cooling and heating using a Peltier module. It was computed through a mathematical model of the system, and then verified in physical model in full scale. Then, the air cooling and heating unit was connected to the system of personal air distribution and equipped with a controller.

ABSTRACT. Subject of this study is the experimental assessment of unsteady displacement ventilation in an office with varying thermal loads. Heat gains are due to solar radiation onto the floor and internal heat sources due to humans and office appliances respectively. The effects of unsteady volume flow rates of supply air on spacial distributions of temperature and velocity of the room air are examined. The test cases are based on results of previous CFD-simulations. Simulative results indicate advantageous conditions for unsteady air supply regarding the removal of thermal load and ventilation effectiveness in comparison to constant volume flow rates of supply air. Unsteady displacement ventilation is constituted in periodic interruptions of the supply air flow. Hence, supply air flow pulsates, in between two pulses of supply air there is a pause without supply. In general, at the same inlet velocity, a pulsed supply air jet induces more room air when compared to jets generated by constant volume flow rates. Parameters for control of the HVAC-system are the periodic time consisting of pulse and pause, the inlet velocity of the pulsed supply air flow, average volume flow rate respectively, of the supply air. The final parameter to be assessed is the temperature of the supply air entering the room.

ABSTRACT. 　In recent years, web traffic data have increased significantly. Therefore, we need to handle large amount of data by using a data communication equipment in the datacenter.　Thus a significant reduction of energy consumption in the data center has been strongly required. There are several methods to reduce energy of computer room air conditioning (CRAC) in data center, such as using local CRAC. Although there are problems that hot air exhausted from the server is not captured to CRAC, which causes CRAC and server operated inefficiency because of the short circuit to the sever. In this study, we assumed a large scale datacenter to reveal the optimal air conditioning control, and the operation mode of the server by using the capture efficiency η. Two types of model were assumed, namely, conventional CRAC and local CRAC. 　In this study, the capture efficiency of CRAC ( -index) is defined as the ratio of air volume of server to that of CRAC. Models for estimating indoor air flow were developed based on the thermal equilibrium in data center. Furthermore, to reveal the differences in conventional CRAC and local CRAC, we constructed a new evaluation model. Also to achieve a suppression of the short circuit. In this evaluation model, by focusing on the air temperature on the air conditioner and the server, it is that to derive the capture efficiency η. 　By creating an evaluation model, it was possible to derive the optimum capture efficiency and conditioning air amount in both conventional and local CRAC.As a result, we made to suppress the short circuit, due to the operation mode of local CRAC and the server. 　This study achieved results in regard to data center model that new evaluation model. We think that this will lead decreasing energy of air conditioning in the future.

ABSTRACT. Performance of diffuse ceiling ventilation with regard to thermal comfort and limits of the cooling capacity of the system was studied in a 97 m2 landscape office. Seven operation scenarios were tested: two for mixing ventilation with ceiling mounted fan coils and five with diffuse ceiling ventilation. The conditions for ventilation air change rates were 1.2, 11.5 and 17.9 h-1, respectively and temperature differences between supply and exhaust ranged between 5.5 and 10.6 K. The vertical room temperature distribution and the air speed in several points in the room were measured. The results show that diffuse ceiling ventilation has substantial potential for landscape office applications because it can provide important cooling capacity while maintaining an acceptable comfort level in the occupied zone. It does not generate draught in the occupied zone even at large temperature differences between supply and exhaust and great air change rates, while the same design parameters caused risk of draught in many points in the case with mixing ventilation. Good mixing in the occupied zone in case of both systems resulted in only small vertical temperature gradients. The results from the study allow extrapolating the design chart q-T for diffuse ceiling ventilation systems for higher ventilation flow rates.

ABSTRACT. In swimming pool facilities ventilation systems are, in addition to water preparation systems, the most vital elements without which the pool cannot operate. Nowadays central ventilation systems, in which one unit prepares the air of equal parameters for the entire pool hall, are used. This article proposes to move away from this approach in favor of a decentralized system. The main principles of the decentralized ventilation system that show its advantages over a centralized system will be presented. Among the biggest advantages that should be mentioned are improving air quality in the occupied zone and ensuring proper parameters for each location in a pool hall. The article presents the results of a simulation in which the energy consumption of heating ventilation air in a typical design of a swimming pool facility has been compared with a decentralized system with a traditional air handling unit and a central system. The results show that decentralized ventilation with properly sized air handling unit provides substantial energy savings, up to 50%, in heating supply air in a pool hall.

ABSTRACT. Ventilation system for the swimming pool is design based on evaporation rate. If the air stream based on the evaporation rate is too low it can cause moisture condensation on the building envelope and to destruction of the construction of the building. If it is to high it leads to oversizing of the ventilation system. It causes high operating costs. There are many formulas to calculate the evaporation rate in the literature. Finding the right formula is very hard, because these relation give different results, which are significantly different from each other. The appropriate formula can help in the proper design of the ventilation system, especially in designing right size of an air handling unit. In finding appropriate formula monitoring of air handling unit in the real facility can be very helpful. The article presents the results of monitoring of water evaporation in the swimming pool facility located in Poznan, Poland, based on the measurements of the parameters of supply and exhaust air in their handling unit and the parameters of the water and the air in the pool hall. The results show that the evaporation rate, according to the literature gives much higher values than those measured. Selection of a proper correlation will lead to correct selection of air handling unit (smaller size), which causes that the HVAC installation for the pool will operate more optimally and effectively.

ABSTRACT. The air quality in commercial aircraft cabins requires thermally comfortable and healthy environment. The circulation of air flow depends on the geometry of the cabin and the air conditioning ducts. This article is concerned with the provision of furniture and proposes a new methodology for the use of efficient and personalized way of the under floor air diffuser to airplane design. In this research will be checked the flow of air and its space used in jet aircraft E170 model with capacity for 70 people manufacturing Embraer, in order to determine through analysis of literature, how to improve the comfort conditions in the cabins, in order to attract passengers and achieve security, energy savings and thermal comfort throughout the flight.

ABSTRACT. Introduction Environmental control system of the aircraft cabin is critical to passenger safety and comfort. Most studies focused on main air supply system controlling cabin environment for thermal comfort and air quality in aircraft. Only a few studied individual air supply system supplying conditioned air directly over a seated passenger’s head. Nozzles are widely used in Boeing and Airbus aircrafts as personal air supply outlets. A passenger can adjust his nozzle’s flow rate and direction in order to achieve their preferred environment. However, a nozzle’s structure is relatively complex and its flow characteristics have not previously been considered in detail. This paper aims to research a nozzle’s flow field characteristics and supports for its effect on a passenger’s thermal comfort and air quality.

Method Measurement on nozzle flow field was carried out in a three-row aircraft cabin. Nozzle jet flow is toward chest of a seated passenger. 16.2° was the angle between nozzle jet flow axis and vertical in terms of a Chinese reference man who is 62kg and 1.7m. Passengers’ surrounding area from waist to head was the focus in thermal comfort study. A nozzle’s flow field in this area was measured with 220 measuring points in four experimental conditions with different air supply temperatures and three conditions with different air supply volumes.

Results and discussion When nozzle air supply temperature was 5℃ lower or higher than cabin temperature, temperature on jet axis from 0.3m to 0.4m away from the nozzle was obviously different with ambient temperature. There was no obvious temperature difference between nozzle jet area from head (0.5m) to waist (1.0m) and ambient area.

When nozzle air supply temperature was 10℃ lower or higher than cabin temperature, temperature difference lower than 2.8℃ set in ASHRAE 161 occurred between nozzle jet area from 0.3m to 0.4m away from the nozzle with ambient cabin environment. And 1℃ occurred between nozzle jet flow area from 0.5m to 0.6m and ambient environment. Nozzle jet flow area from 0.7m to 1.0m had the same temperature with ambient environment.

The airflow velocity distribution at different cross-sections was axisymmetric. Different air supply temperatures did not make different velocity fields with same air supply volume. Different air supply volumes made different velocity fields with same air supply temperature. Fitting function describing a nozzle’s velocity field was calculated by using the theoretical formula.

Conclusions Temperature field and velocity field are all known for a typical nozzle in Boeing and Airbus commercial aircrafts. A nozzle’s velocity flow is in line with the attenuation law of circular jet flow. Due to the nozzle’s special attenuation law, non-uniform temperature field in a seated passenger’s surrounding area does not exceed the limit in ASHRAE161 when nozzle air supply temperature difference is not over than 10 ℃ comparing with cabin temperature. Nozzle air supply cannot make significant ‘cool’ or ‘warm’ effect on a passenger’s thermal comfort in terms of temperature. This is important to optimize nozzle air supply system in aircraft cabins.

ABSTRACT. Introduction Three types of tracer gas test are, until now, mentioned in international standards: 1) Controlled injection at constant indoor concentration;

2) Injection at constant flow rate on time long enough to reach a constant concentration

3) Transient injection, just until reaching a high enough indoor concentration and recording of the decontamination curve (linear in semi-logarithmic scale). A fourth method is proposed in this paper: it is based on the same scenario as the third method, but with careful weighting of the mass of tracer gas (CO2) injected and on the integration of the curve of indoor concentration on the whole testing period. This fourth method appears as cheaper (CO2 is almost free and cheap and reliable CO2 sensors are now currently available) and more accurate than other ones. Moreover, it might be combined with a co-heating test if the CO2 is directly produced by combustion on site… Methods The test must include three consecutive periods: 1) Recording of all relevant variables before any injection in order to identify as well as possible the initial conditions ((hopefully in steady state regime); 2) CO2 injection until reaching a tolerable peak of indoor concentration (according to occupants and/or sensors tolerances); 3) Decontamination until some optimal concentration level (the way of identifying of this optimum will be explained in the paper). The concentration peak is used to identify the “effective” volume of the building zone considered; this volume, associated to the final concentration, is used to calculate the amount of CO2 remaining inside the zone at the end of the test. The total mass of renovation air is then deduced from the corresponding CO2 mass balance. The CO2 can be injected from a bottle or directly produced by combustion on site. In the latter case, the tracer gas method combined with a co-heating test. As shown in the paper, it can be done, for example, with a current camping butane cooker. This device is a very well defined source of heat, CO2 and H20. From the weighting of this device and continuous recording of air temperature, CO2 concentration and humidity ratio, three significant (energy, CO2 and water) balances are established in such a way to verify and tune a reference simulation model of the building zone.

Results Both approaches (CO2 alone and combined with co-heating) were tested in laboratory conditions and on site. The use of CO2 alone was tested, first in a large laboratory building and then in a real office building where the actual ventilation flow rate was directly measurable. The co-heating by combustion of gas butane was tested in a climatic room and then inside a solar passive house. Prospective simulations were also performed in other reference buildings.

Conclusions CO2 appears as a very promising tracer. A careful weighting all along the injection period associated to the integration of the indoor concentration all along the test period makes possible a very accurate identification of the air renewal. Such tracer gas test can be combined with a co-heating test. An example of such combination can be realized with the help of a simple camping cooker supplied by gas butane.

ABSTRACT. INTRODUCTION The energy consumption of data centers is increasing rapidly and has become a global concern in recent years. Nearly 50% of total energy use in a dater center is consumed by the cooling system. Therefore, it is necessary to develop free cooling system for data centers, which can use the outdoor cooling source in cold seasons. METHODS In this paper, recent experimental results of the integrated system of mechanical refrigeration and thermosyphon are presented. The experiments are conducted in a laboratory based on heat balance method. Moreover, the system is tested in a dater center in three periods of time in summer, autumn and winter, respectively, in Beijing. In this field test, the inlet and outlet temperatures of the system are measured by temperature recorders and the input power is recorded by an electricity meter. RESULTS AND DISCUSSIONS The testing results with heat balance method show that the cooling capacity reaches 4.24 kW and the EER is 9.5 when indoor and outdoor temperature difference is 9 oC. The field test results show that the system can work reliably for long time. The average EER in summer, autumn and winter is 3.52, 5.19 and 10.50, respectively. It can be seen that the EER of the system is much higher than traditional air conditioners throughout most of the year.

ABSTRACT. The model which is presented in this paper was sustained by two numerical models: scroll compressor and air cooled condenser equipment.

By using this model it is possible to obtain the thermodynamic process energy efficiency performances, for the analyzed system, in a simple way and with less input parameters.

With the help of this model it was possible to have polynomial equations and graphics in order to help us find the performances of the simulated refrigeration system. With these polynomial equations it is possible to verify the system in different working conditions.

This model can be generalized to all the one stage refrigeration systems, to test and verify the energy efficiency performances and the problems that may occur during the working period.

ABSTRACT. INTRODUCTION Our national husbandry belongs among economies with the biggest energy consumption per an inhabitant. Slovak republic consumes for making of product’s unit approximately twice more energy than the average in forward European countries. Such a big reserves, that we have to achieve in the area of effective increasing of energy utilization are not possible only by administrative way, but by establishing of new technical solutions into a general practice too. In a part of large-area industry operations, the new technical solution lies in the combination heating system by suspendable radiant panels with ventilation by air handling unit with integrated device for heat recovery, which considerably reduces the operation costs.

METHODS The advantages of this combination will be shown as a computational example, as well as experimental measurements. The example is based on the design of ventilation ducts with a height of 7,20 m below the hall roof deck and 6,00 m in height suspension of drall diffusers. Basic settings for the blades outlet temperature + 3 °C is 0 - 45°, the temperature + 3° to + 16 °C continuously to the outlet angle of 60°. With increasing height of the large-area industry hall, respectively hanging diffusers, increases the angle of the blades set at 90°. In the experimental measurements the main parameters of internal environment were monitored and evaluated.

RESULTS The physical parameters of indoor air were measured in two levels (0,15 m and 1,70 m above the floor). It could be confess, that the temperature was about + 16 °C (assembly hall) and velocity in a working area was under 0,3 m/s. All of these results suited the criteria established by national legislation.

CONCLUSIONS For proper operation and functionality designed ventilation systems are needed in this system the measurement and control system, which ensures continuous and reliable operation of systems. This is only the way, how to ensure optimal internal environment for man in his working area, while at the lowest possible power consumption.

ABSTRACT. The trend of the building sector towards the achievement of Net Zero Energy has accelerated in the last years and, the introduction of this theme into local European legislation is ongoing. However it is not only conventional constructions that need to be directed towards the Net Zero target: also the sector of pre-fabrication of temporary housing solutions would need to address the new concept of Net Zero Energy. The paper presents a case-study of a pre-fabricated module aiming to assess its energy performances and to quantify the potential of ventilative natural cooling to improve it. Built in Messina (Sicily, Italy) at the Italian National Research Council, it was designed in the context of the research project: “CNR per il Mezzogiorno – Tecnologie avanzate per l’efficienza energetica e la mobilità ad impatto zero”. Some particular features of the building (such as the modularity, the prefabrication, the rapidity of assembly, the possibility of being built on disconnected soils and the absence of maintenance) identify an effective use as a temporary housing solution for e.g. workers in proximity of an isolated working place or in emergency situations such as earthquakes and natural disasters. The entire structure of the living module is realized from pultruded fiber reinforced materials, with U value of the opaque structures close to 0.3 W/(m2 K). The module develops on a single level of about 45 m2, including 2 rooms, a central and a technical room. The technical room has an area of about 9 m2 while the main one has a surface of 36 m2. The building has two main façades almost fully glazed. The south-est facing window to wall area ratio is about 90% (nearly 15 m2 of glazed area, 20% openable). The back one reaches around 65% of window to wall ratio. The photovoltaic system has a peak power of 3.5 kWp; a geothermal heat pump covers heating and cooling needs. The building was simulated in energy plus environment, validated on monitored data obtaining small and acceptable differences between monitored and simulated data. Results identify the building as a plus zero energy building, with generation above overall consumptions by more than 30% of the overall electricity consumption (around 75 kWhe/m2). Natural ventilation in the hot Sicilian climate would prove essential to reduce thermal loads from 31 to around 24 kWhe/(m2) in a year mainly during mid-seasons, due to both the features of the climate and the low-mass\highly glazed envelope.

ABSTRACT. Indoor environment in buildings affects human comfort; however, most literature is aimed at environmental conditions dealing with thermal, acoustical, visual, and air quality parameters. Since a majority of domestic energy consumption is related to water and spatial heating, most research on comfort has focused on its thermal dimension, which in its turn is heavily influenced by physiological aspects while socio-psycho-cultural aspects are often disregarded. Similarly, energy behaviour is researched with a focus on economics and engineering. The link between energy consumption and comfort tends to be bridged by the thermal parameter since: a) heating represents the majority of the consumption and b) people mainly report thermal elements as a theme in home comfort-making, such as clothing, bathing, place temperature, and ventilation. This paper is a literature study aimed at exploring further dimensions of comfort and energy consumption at homes in terms of their interactions with each other and as multidisciplinary subjects.
It is suggested that comfort and energy behaviours are more complex than its technical-physiological parameters and that when studying both topics as multidimensional and interrelating concepts, missing links from other disciplines could be discovered, which can allow for more comfortable and healthy environments, and for more comprehensive strategies for better energy behaviours.

ABSTRACT. Japan is affected by continental climate during winters and oceanic climate during summers. As a result, the country experiences four distinct seasons, as well as the most dramatic shift in annual climate in the world. Japan is characterized by humid, hot summers and cold winters; there are also large differences across regional climate zones. However, with increases in the use of air conditioners, comfortable indoor temperatures can be maintained all of the time in recent years. In Japan, air conditioners are commonly selected on the basis of the calculating methods of cooling and heating area for room air conditioners created in 1964 (a standard of reference based on the size of a given room). It is commonly called "tatami number guideline". This standard was established on the basis of homes with poor insulation, which was typical at that time. It is reported that if the same reference guide was applied to modern, super-insulated homes, an air conditioner with excessive capacity will be selected, resulting in inefficiency because of excessive CO2 emissions and power consumption. For efficient air conditioner usage, other factors, such as characteristics of the house and lifestyle of the residents, must be considered in addition to the size of the room. It is important to install air conditioners with capacities that meet the dwelling habits of consumers. In response to this, we conducted research to better grasp the current methodology used to select air conditioner , and the manner in which consumers use them. Results of telephone interviews with electronics stores revealed a correlation between warmer climates and the likelihood of stores to recommend air conditioners with capacities larger than those recommended by the tatami number guideline. Moreover, some of these stores mentioned that they recommended these air conditioners because they were unable to assess the lifestyle of consumers. In addition, results of an online survey of general consumers showed a trend of consumers living in warm climate areas using air conditioners with capacities larger than those recommended by the tatami number guideline. There were regional differences in seasonal air conditioner demand. However, there were no differences with respect to usage time (time of day) and thermostat temperature. The time of air conditioner usage (time of day) was directly impacted by the number of hours spent at home by respondents during weekdays and weekends.

ABSTRACT. An increasing body of research is underlying the need to foster energy behaviors and interaction with technology as a way to achieve energy savings in office buildings. However, engaging office users into more “forgiving” comfort-adaptive behavior is not a trivial task, since neither consequences nor benefits for changing behavior have visible or tangible effects on them personally. Since the 70’s, survey studies in the field of building science have been used to gain better understanding of multidisciplinary drivers of occupant behavior with respect to comfort and energy requirements in buildings. Rather than focusing on individual behaviors – and influencing factors – purpose of this survey research is to provide quantitative descriptions on the collective and social motivations within the complexity of different social groups in working environment, under different geographical context, culture and norms. The resultant questionnaire survey emerges as a combination of traditional and adaptive comfort theories, merged with social science theory. The questionnaire explores to what extent the occupant energy-related behavior in working spaces is driven by a motivational sphere influenced by i) comfort requirements, ii) habits, iii) intentions and iv) actual control of building systems. The key elements of the proposed occupant behavior motivational framework are grounded on the DNAS framework for energy-related behaviors in buildings. Goal of the study is to construct an additional layer of standardized knowledge to enrich the state-of-the-art on energy-related behavior in office buildings.

ABSTRACT. In order to make better and more realistic predictions of energy consumption in dwellings, more knowledge is needed about how individuals and households control the indoor environment. A questionnaire survey was conducted with the objective of studying the interest and actions taken in relation to indoor temperature, air quality and energy consumption by Danish house owners living in single-family detached houses with district heating. The house owners state that they are interested in, and concerned about, the indoor temperature and air quality and that it is an important element in caring for each other in the family. Actions are taken in relation to the temperature in the way that house owners are trying to keep different temperatures in differently heated rooms, e.g. to sleep in a cool bedroom or to save heat. Besides they wear warmer clothing, slippers or thick socks indoors during the winter compared with the rest of the year. Actions are taken to improve the air quality by the majority of the house owners by opening windows. The most frequent reasons for opening windows once or several times a day was “to get fresh air” and “in relation to showering”. House owners are interested in saving energy for the sake of the environment and for their own economy, and quite a lot of households indicate that they know their own energy consumption, though only few follow it closely. Thus being concerned about energy is not necessarily related to an interest in detailed feedback on one’s own energy consumption. Results show that well-planned communication about feedback possibilities is important. Women and men answer slightly differently to some of the questions, e.g. women are more active in airing, and they wear warmer clothing, whereas men are more actively following their energy consumption.

ABSTRACT. The occupancy pattern and the energy supplied to a building due to metabolic activity are relevant inputs to models used for control applications and energy performance assessment of occupied buildings. It is very difficult to accurately estimate the contribution due to metabolic activity to the energy balance of occupied spaces. The main difficulties are related to determining how much energy each user supplies, and how many users are in the room. Usual assumptions and approximations to estimate these contributions bring high contributions to the uncertainty budget of the estimated parameters and outputs of these models. The work reported in this paper studied different options to estimate the level of occupancy of rooms in an office building from experimental campaigns. The most efficient way to represent this level has been investigated. Efficiency is here referred to accuracy, cost effectiveness and intrusiveness of measurements, which is very useful in terms of commercial applications. Measurements of C02 concentration and electricity consumed by computers have been considered as alternative indicators of the occupancy level. Both indicators have advantages and drawbacks which are analysed in this work. In principle C02 concentration is an evident indicator of human presence. However it is also influenced by other variables such as the status of doors, windows and mechanical ventilation system. Consequently these other variables have been taken into account in the study based on C02 concentration. The use of computers has been considered also as a potential indicator of occupancy taking into account that this room is used as an office. Each user has a computer switched on when he or she is in the room, then there must be a relationship between electricity consumption due to computer use and the number of users in the room. It is also known that when each computer is switched on its electricity consumption varies in a certain interval depending on the activity of its CPU. In both cases (using C02 concentration or electricity consumption of computers) intervals when the room is empty for sure and intervals when the room is occupied for sure have been identified. This study is based on histograms that represent the occurrences of each interval of the considered indicator along the studied period. The histograms considering only nights aim to identify the level of the considered indicator when the room is empty for sure. The histograms considering only periods when the light are switched on aim to identify the level of these indicators when the room is occupied for sure. Afterwards the identified intervals have been used to obtain occupancy patterns of the rooms. Information previously available from the rooms such as typical working period, lunch time when the rooms are empty, holidays weekends, etc., have been used to validate the results. Data corresponding to a period of seven years, recorded while the building was regularly used, have been employed. First analysis considers all these available data giving robustness to the results. The accuracy obtained when shorter experimental campaigns are used, has been studied.

ABSTRACT. Building occupants’ personal attitudes have been widely acknowledged to affect building overall thermal-energy performance and the reliability of energy consumption prediction. Human attitudes are also able to strongly impact on the effectiveness of energy efficiency strategies in both new and existing buildings, if they drive the occupant toward non-aware behaviors. in this view, key research efforts were carried out in order to clusterize occupants into several peers’ groups assumed to behave the same, by considering their social attitudes, their age, gender, working or residential attitudes, clothing features, etc. Nevertheless, despite several social and behavioral categories could facilitate the prediction of peers’ thermal-energy attitudes, almost unpredictable further variables still play a key role hugely affecting building indoor environmental conditions. In this view, the purpose of this work is to point out the importance of peers’ daily behavior and specific human attitudes in determining building thermal-energy performance and energy need, in terms of (i) indoor environmental conditions and (ii) electricity consumption. To this aim, a continuously monitored case study office building located in central Italy is selected. In particular, identical office rooms with exactly the same end-use and technical-architectural features are considered. Occupants could be considered as peers for carrying out the same job, having the same occupancy schedule, being the same age and with the same educational background. Nevertheless, they showed a huge differential personal attitude, indoor thermal perception and management of the microclimate conditions in terms of lighting and thermal profiles. Every room has been monitored in terms of equipment electricity consumption, occupants’ presence, opening rate of doors and windows, and visual and thermal comfort parameters inside each room. To this aim, a preliminary continuous indoor monitoring in summer conditions is carried out for the scope of this work. Indoor characterization of each office is also compared to outdoor continuously monitored weather conditions, in order to find out also peers’ different attitudes in reacting to outdoor forcings and natural resources such as daylighting and natural ventilation. The main findings of this study showed that personal behavior is a key variable which is very difficult to predict by means of classic reliable models because also personal clusters of peers were found to behave completely differently from several perspectives, e.g. lighting management, openings’ behavior, thermal indoor management, electricity need for their job appliances.

ABSTRACT. The status on implementation of Nearly zero energy buildings (NZEB) on national level varies with different national primary energy requirement on 20 kWh/m2 in Denmark to 160 kWh/m2 in Austria.

Such a difference shows that the interpretation of NZEB is widely different in the member state and has not been the original intention from the European Commission in the development of NZEB requirement in the Energy Performance of Buildings Directive (EPBD).

Detailed studies has been made and shows that there is a difference in the structure of the national legislation, where additional requirement – that are not included in the requirement to NZEB buildings – will secure an energy efficient performance of buildings

Other studies shows that only a few member states has included supplementary requirement to indoor climate in existing and NZEB buildings. This is also a challenge as the EPBD, clearly require that member states shall take account of general indoor climate conditions.

This paper will give an overview of implementation of NZEB on national level and will take its starting point in the BPIE studies on “Implementation of Nearly Zero Energy Buildings” and “Indoor air quality, Thermal comfort and daylight”. It will elaborate on the specific requirement in a few countries and will based on cases and demonstration projects bring forward proposals for a common interpretation for NZEB houses.

ABSTRACT. Ongoing commissioning based on calibrated building energy models is one of the most promising means to improve the energy performance of existing buildings. Many calibration methods in the literature relied on whole-building utility data to calibrate building energy models. Recent studies revealed that only using this approach could result in offsetting errors occurring at sub-utility levels. The number of candidate measurement points required for bottom-up calibration is large. Fortunately, building automation systems (BASs), common in many commercial/institutional buildings, can provide some of the required data. Using inputs generated from trend data and calibrating the zone level first often yielded a calibrated model at the system level. The paper applies the proposed method to a new research building.

ABSTRACT. Energy efficiency in buildings should not be reached on the expense of indoor environmental quality (IEQ). This statement is often used in connection to design and certification of sustainable buildings. The fact that it is also valid during the actual operation seems to be often forgotten. Nodaway’s energy management and operational diagnostics focus mostly on energy consumption. Consequently also present key figures comprise performance indicators related to energy use. The fact that modern buildings are not spared from IEQ related problems indicates that there is a need for joint assessment of energy and IEQ performance. The aim of this paper was to review relevant literature to form a scientific background for development of key figures enabling the joint assessment of energy and IEQ. The review resulted in forty cited publications. Majority of them focused explicitly on energy performance and indoor environment was mentioned only marginally or was not mentioned at all. We can also conclude that energy related key figures are well established and used for standard energy management as well as in different optimization algorithms involving analysis of measurements and calibrated simulations. One publication was identified that integrates thermal comfort into broader matrix of key figures. Methods for long-term evaluation of IEQ indicators suggested by standard EN 15251 seems to be usable for determination of key figures for joint assessment. Further research is needed to determine and test key figures that would directly combine performance indicators related to both energy use and IEQ.

ABSTRACT. With the increase of building certification systems worldwide, the evaluation of building performance has been standardized. These certifications provide some points for indoor air quality and thermal comfort in reference to standards like ASHRAE 55 and ISO 7730. However, the assessment is performed taking into account whether the design fulfils the requirements of the standards, in addition to measurements and a survey of the occupants’ thermal comfort (Miljobyggnad Gold). In fact, this only ensures that the requirements are met at the time of the inspection and little is known about the building’s performance after the inspection.

In order to analyse the thermal comfort of occupants, a lot of studies have been done applying either the rational or the adaptive approach. The rational approach is based on a heat balance model of the human body, while the adaptive approach concentrates on what happens outside controlled environments taking into account the humans’ interaction with their surroundings.

This paper presents a new methodology to assess building performance in a holistic manner. The key parameters that are considered include the energy consumption, the occupants’ thermal comfort, the environmental impact and the corresponding cost. An office building located in Stockholm, Sweden is used as a case study. The energy consumption is measured through installed energy meters, whereas the thermal comfort is assessed using the degree hours criteria, described in standard EN 15251(2007).

The results allow a better understanding of the correlation between the amount of consumed energy (kWh per square meter) and the quality of the delivered service. Moreover, a long term monitoring of the building leads to a better understanding of how the building should be operated and in some instances to energy savings without compromising on the quality.

ABSTRACT. The building stock is one of the major energy consumers in Europe accounting for about 40% of total final energy consumption and 55% of electricity. Moreover, buildings are the largest end use sector and especially residential buildings account for two thirds of this energy use. Despite the fact that building characteristics play a major role in a dwelling’s energy consumption, occupant characteristics and behaviour significantly affect this energy use as well. The Ecommon campaign wirelessly monitored 32 residential dwellings (grouped according to their ventilation system and energy label) for 6 months in the Netherlands, capturing quantitative data (temperature, CO2, humidity, movement, boiler and ventilation systems electricity consumption, total electricity and gas consumption on the meter and real time total electricity consumption) and qualitative data (comfort perception, actions taken like closing and opening windows, thermostat use, putting on or off clothes, clothing ensemble and metabolic activity). The quantitative data were recorded every 5 minutes while the qualitative were recorded in sessions of 1 week per dwelling. Additionally in the beginning of the campaign a survey was given to the tenants with questions on income, gender, education level, thermostat and ventilation preferences, types of electric appliances, bathing patterns and other related data. This paper describes the experimental set up of the monitoring campaign, the results of the initial survey and the results on the temperature, CO2 and occupancy profiles for each type of room (living room, kitchen, bedroom and study room) for the 32 dwellings. The temperature profiles show that these residential dwellings have higher temperatures through the whole day than the common assumption of the daily average of 18 o C that is suggested for the calculations of the national simulation software. Furthermore during the initial survey the tenants of the A labelled dwellings indicated the highest thermostat settings (minimum 21 o C) compared to the poorly insulated dwellings (maximum 20 o C). CO2 concentrations showed that dwellings with balanced ventilation had the best performance leading to a minimal amount of hours with CO2 excess. Free running buildings had the worst performance leading to large number of hours that CO2 exceeded the threshold of 1200 ppm.

ABSTRACT. In Japan, the energy consumption has been increased in residential sector. This paper presents the analysis results about the difference in energy consumption realized by architectural measures and occupant behavior based lifestyle to examine energy saving measures in the future residential sector.

Numerical simulations were executed to clarify the thermal environment and the energy consumption considering architectural measures and occupant behavior based lifestyle. The target apartment house located in Tokyo, Japan has reinforced concrete construction and its total area is 3,745 m2 and the total number of households is 43. One of the dwelling unit, located in between adjacent units on a middle floor, was simulated for this study.

The building model was made reflecting material characteristics. Also, the schedules of each resident behavior and home appliance, including room air conditioner and hot water heater, were set as a target dwelling unit by the simulation. AMeDAS (Automated Meteorological Data Acquisition System in Japan)data was used as the weather condition.

Four-persons household case was thought as the general case. Recently the resident number has been decreasing in Japan. So one-person household case and two-persons household case were studied as well. Six analysis models were established: Standard model, High insulation model, High efficiency home appliance model, High insulation and High efficiency home appliance model, Energy saving action model 1 and 2.

The schedules of usages for home appliance, room air conditioner, and hot water heater were the same in all models. Total number of home appliance were 19 kinds. However, the capacities of home appliance, such as refrigerator, washing machine and so on, were different depending on the resident number. Therefore the energy consumption of home appliance was different depending on simulation model cases.

The energy consumption for air conditioning and hot water suppl were markedly different depending on the resident number. There was not much difference between one-person household case and two-persons household case in heating load. On the other hand, indoor heat generation rates at four-persons household increased compared to that in the other households since the resident number was large and high power home appliance use. It was resulted in that heating load was increased for about 23 % and cooling load was increased for about 53 % compared to the other cases.

The energy consumption was reduced 7.3% by highly insulating model. It was reduced 24.5% in high efficiency home appliance model, and 25.9% in case of adapting both of them. In addition, when thermal barrier curtains were used while air conditioner is operating, the energy consumption was reduced 8.1 %. In terms of the energy conservation, high efficiency home appliance model was better in comparison with high insulation model. Heat load was reduced much on high insulation model. When insulation repair could not be done, it was effective that ‘turning the light off frequently’ and ‘closing a thermal barrier curtain during air conditioner operation’ to get energy conservation.

ABSTRACT. Accurate forecasts of the time-varying demands for electricity and hot water, as well as the air-conditioning (A/C) load, become crucial for designing reliable smart grid systems coupled with renewable energy sources. In particular, the time-series demands in residences has been known to be highly diverse and heterogeneous across households, weather conditions, and building specifications, partly because of the diverse behaviour and preferences of the occupants, prompting the development of proper estimation methodologies. Meanwhile, there have been various field observations on the characteristics of the occupants’ behaviour associated with the A/C load and energy usage for past decades, and many of them have suggested that the probabilities of occupants’ actions such as switching-on an air conditioner and opening a window, can be modeled by logistic models as functions of environmental variables, such as indoor air temperature and external illuminance. However, this type of studies has been still dominated by observations in mid-latitude developed countries. Under these circumstances, the authors performed a series of field observation of occupants’ behaviour towards space cooling in residences located in two countries with contrasting climate conditions, namely Fukuoka, Japan in the temperate zone and Kuala Lumpur, Malaysia in the tropical zone, aiming to 1) provide event-base data of occupants’ behavior of A/C usage for developing stochastic models for the building energy simulations, and 2) deepen the understanding of cross-cultural difference of occupants’ behavior caused by the climate conditions. The observation in Japan was conducted in 20 dwellings located on the southern outskirts of Fukuoka City over approximately three months during the summer. In contrast, the measurement in Malaysia was conducted in 27 dwellings located in a public low-cost housing complex in Kuala Lumpur. The measurement period of each dwelling in Malaysia varies from about one to two months. The time-series variations of air temperature of the living room, and the outlet of the air-conditioner installed in the living room, were measured in each dwelling in Japan, whilst the measurement in a bed room was added in case of Malaysia. In addition, detailed questionnaire surveys were completed by an occupant of each home (usually the housewife) to capture demographic information, usual behaviour schedules, perception of thermal comfort, and approach to the A/C usage. Based on the estimated schedule data of A/C usage, we sampled A/C events, defined as the period from when occupants turned on an air-conditioner until they turned it off. The data of each A/C event were connected with the data of start time, duration of the event, outdoor and room air temperature of start time, and average temperature of both the outdoor air and the room air for the duration. The statistical analysis of the observations in these two countries was complied in terms of the following statistics, namely total duration of A/C events in a day, number of A/C events in a day, and room air temperature when A/C operated. The relationships between the previous variables and the outdoor air temperature and time slot were investigated.

ABSTRACT. Some essential objectives in energy sector may be considered to provide low-carbon cities, increase share of renewables and maintain relatively higher efficiencies in both fuel consumption and energy utilization fields. A thermal load calculation plays a key role for achieving these objectives by determining amount of energy consumption in related sectors. Due to high energy consumption (32%) and high carbon dioxide emission (30%) percentages in global scale, thermal load calculations were carried out for an educational building while these calculations were used to size a HVAC system, which amounts to nearly half of total building’s energy consumption. Two types of procedures, namely on site measurement and forecasting, can be used in thermal load calculations. Since onsite measurement procedure is not economically feasible and requires long time, studies done up to date concentrate on forecasting by statistical methods or simulation programs. In this study, four different methods are carried out for determining the capacity of a split type air conditioner unit in a single room of Ege University’s mechanical engineering department building. The methods considered include (i) a Turkish Standard (TS) 825 simulation program, that is quite popular in Turkey, (ii) a marketplace calculation tool, (iii) an Open Studio program based on Energy Plus and (iv) ASHRAE Handbook 2013 residential cooling and heating load calculations procedure.

In this study, the building envelope, internal heat gains, ventilation, infiltration and atmospheric conditions were regarded as input parameters first. Then, both maximum heat gain and heat loss amounts in terms of peak loads were calculated using four different methods for sizing the HVAC system. Finally, the calculation steps of the methods used along with their basic advantages and disadvantages were discussed. It may be concluded that ASHRAE Handbook 2013 residential cooling and heating load calculations procedure was chosen as a main method because it offered more accurate calculation.

ABSTRACT. With the extremely low energy consumption, Ultra-low energy building has become an important direction of the construction development in recent years. The mechanical ventilation system has becoming a key factor that affecting the quality of indoor air and the overall energy consumption level of the building because of the high-level air tightness. This paper focuses on the impact of actual operating schedule when calculating the preheating load in cold and severe cold regions. Thus, a correcting calculation and difference analysis on mechanical ventilation analysis between office building and residential building will be proposed aiming at different operating schedule.

ABSTRACT. This paper is concerned with the development of data driven predictive models capable of forecasting building heating loads. A novel methodology is proposed for developing predictive models by use of reference benchmark building simulation model as part of the predictive model methodology development. The research is motivated by the need to predict the thermal loads of commercial buildings in an effective and time efficient manner. These predictions can be used for enhanced control of HVAC systems with the potential for more efficient operation and decreased energy consumption. Commercial buildings incorporate BEM (Building Energy Management) systems to control HVAC systems and to monitor indoor environment conditions. In practice, incomplete datasets are common when extracting data from BEM systems, which leads to challenges when developing predictive models. The proposed development of predictive models for estimating building thermal loads consists of two stages: (1) selection of input variables that will be utilised in the predictive models and (2) development of the predictive models. In order to select the appropriate input variables, complete datasets are required. To address the lack of complete and reliable datasets from actual building BEM systems, a detailed representation of a reference building using EnergyPlus was implemented as a benchmark. Data analysis of the simulated results and of the dataset obtained from the actual BEM system is used to detect inter-relationships between variables. Investigation of linear and monotonic correlations is performed by calculating the Pearson and Spearman correlation coefficients, respectively. The results of the process indicate that ambient temperature and building zone temperature are the predominant variables that should be considered as input variables to the predictive model. Once the input variables for the predictive models are identified, various models are developed by implementing both regression-based and machine learning prediction methods. Initially, different regression models are investigated for their ability to forecast building heating loads when implementing real and simulated datasets. Subsequently, machine learning models are examined. The most suitable model is selected by comparing the accuracy of the predictions. The model selected will be transferred to other commercial building types in order to capture the sensitivity to generalisation of the approach and its associated prediction accuracy. The challenges and issues faced during the development of the models are summarised.

ABSTRACT. INTRODUCTION The conservation of cultural heritage inside historic buildings is a task with different restrictions. First of all, climate conditions which keep the origin state of the materials are needed. To avoid damage by moisture, frost, dryness, sponge, a combination of temperature and humidity in an accepted range is needed. Furthermore fast fluctuations of temperature or humidity have to be avoided, since a change in temperature leads to energy transports and in humidity to mass transports in the materials, which can cause damage. Despite the restrictions of the climate only limited HVAC systems are available, due to the preservation of the building stock and installation costs. With those restrictions and the high requirements to temperature and humidity as also high running costs, the usage of the systems should be optimized. The state of the art usage with thresholds for the different intervention tasks is not avoiding fast changes, considering the room’s climate behavior nor considering future weather conditions, which leads to inappropriate and unnecessary usage of heating or ventilating systems. METHODS In order to plan an optimized usage of existing HVAC systems, a model predictive controller is a promising and in different applications established approach. For predicting the future climate states, a model of the climate behavior and a weather forecast is needed. Because the effort to parameterize a building model is very high (considering building a 3D model, including building and stock materials and parameterizing used HVAC systems) and resulting models need a high processing power, other approaches are considered. In the presented application, climate and actor data were already captured over the last two years, so the available data may be used to build a data driven model for the application. By using methods of neuroevolution, an artificial neural network is build by using evolutionary algorithms to represent the buildings behavior and also adapt the weather forecast to a better local state. By using the accomplished model, the usage of radiators and ventilation is planned in respect to future climate states. RESULTS AND DISCUSSION By using an artificial neural network in order to find a dynamic model of the building, the effort for the design of a model predictive controller can be significantly reduced, although collected data of the application is needed in forehand. For new planned buildings, where a model of the building is available, these models will be more feasible. CONCLUSION By adjusting the goals (like energy efficiency, climate goals or reducing changes in climate states) of the predictive controller the user may adapt the solution. By planning the usage of the HVAC systems, it is far more possible to reach these goals with the limited systems while optimizing the usage.

ABSTRACT. Introduction For the cooling of non-industrial buildings is needed about 105 TWh in Europe every year. That in turn corresponds to energy procurement costs up to 18 billion euros. With a view to conserving resources and reducing CO2 emissions, there is great potential for optimization in order to minimize the cooling energy consumption. Methods The previous power control of an air cooler in the secondary circuit (consumer side) has two classical control method, find the both cooling and dehumidification of the air in central air conditioning sys-tems application. First, a change of the coolant inlet temperature at a constant mass flow takes place (temperature con-trol). In partial load operation, the water temperature is above the dew point of the air, creating a de-humidification of the air is avoided. But if a dehumidification of the air is necessary, the air flow to be cooled to the dew point line. As a result, the air is too cold. Additional is a reheating of air required. Second, the power control is carried out by changing the mass flow with constant coolant inlet tem-perature of 6 °C, it means flow control. That means, the air is dehumidified even when this is not nec-essary for reasons of comfort and it is significantly more cooling energy consumed, than to cool the air. In order to minimize the disadvantages of both classical methods and to realize the potential savings, a concept for the optimal conditioning of room air has been developed with the aid of a model-based control approach. This technology mixes not conditioned air with the cooled and if necessary dehu-midified air from the heat exchanger behind the radiator. This is realized via an air bypass. The basic is a finned tube cross counterflow heat exchanger designed by the method of an infinitesi-mal segment of the heat exchanger according to the dissertation of Wolfgang Wiening. An extension of the components that influence: the models of a three-way valve, a two-way valve and an air bypass damper, complete the general system as a whole in the form of a state space model and form the basis for the systematic controller design. The control strategy in this case is a model-based multivariable approach, whereby a systematic de-sign is made possible by utilizing the plant structure and the known system parameters. Based on a linear-quadratic control structure (LQR, Riccati equation) finds an optimal settling of a desired operat-ing point instead. Results By applying the new technology for targeted control of temperature and absolute humidity of the room air, the energy consumption for the air conditioning reduce up to 10%, based on the final ener-gy demand. This means a reduction of the final electric energy up to 10,200 GWh and CO2 emissions by up to 5,946,600 tons per year for Europe. Assuming an average price of 0,201 €/kWh in Europe (EU 27), this represents a potential saving of up to € 2 billion per year. Conclusion The aim is to develop a model-based linear-quadratic control structure to compensate a defined operating point to achieve the comfort without additional reheating. A reduction of the final energy demand by up to 10% is possible.

ABSTRACT. Recent advances of environmental control technologies, the potential of advanced electronics, and innovations in the digital realm have led to many new practical opportunities to reduce the heating demand of buildings. 'Smart' and advanced thermostats are a fast growing market and attract start-ups as well as big players in computer engineering. The applied technologies follow different paths to achieve energy savings, the use of advanced control systems is one important direction of research. In this context, predictive control algorithms show promising results with considerable optimization potential and the capacity to accommodate a wide range of input parameters. In the present contribution, we describe the development of an advanced control algorithm that, starting from an actual room's comprehensive thermal characterization, derives a simplified mathematical model. Moreover, the procedure involves a co-simulation setup that incorporates the implementation of a realistic dynamic heater behavior. Heating demand with different control algorithms from simple 2-point switching control, analogue PI-controller, to predictive control and model predictive control (MPC) strategy are implemented and compared. Together with the control algorithms, the dynamic thermal characteristics of the room heating elements, realized as radiators or floor heating, are modeled with their different time constants for heating up and cooling down and considerably different orders of time constants. The energy saving potential of the proposed approach is documented via comparative simulation studies.

ABSTRACT. INTRODUCTION Nearly one-third of global energy consumption comes from the building sector. In cold climate countries around 50% of energy demand in buildings is directly associated with space heating, ventilation and air conditioning (HVAC). Thus, development of energy efficient buildings represents a great concern and has become the focus of many research activities. As a result, in addition to the use of high-performance construction materials for new buildings and retrofitting the old ones, significant efforts have been also made to optimize operation of HVAC systems using smart controllers instead of conventional ones. This article demonstrates the advantage of model predictive control (MPC) as an alternative to an already-existing conventional control system, in terms of total energy consumption and comfort criteria. In our case study, we consider one office in the main building of the E.ON Energy Research Center in Aachen, Germany.

METHOD A heat transfer model for building thermal elements using the lumped-capacitance method has been formulated, where the air and walls are assumed to have uniform temperatures across their volumes. This simplification helps us to obtain a fast and low-order model, which is appropriate for our control purposes. The model takes following terms into account: (a) conduction through walls and window, (b) convection due to the air movement, (c) solar radiation through the window, (d) absorption of solar radiation in external walls, (e) heat supplied by HVAC systems, (f) internal heat gains, (g) internal surface radiation of walls, and (h) heat storage capacity of walls and air. After developing a comprehensive model, unknown parameters have been estimated by minimization of errors between measured and simulated temperatures. We used the monitored data for one week during the heating period for estimation and different data from another week (also during the heating period) for validation of our estimations. We built our model in Simulink and used YALMIP toolbox to set the optimization problem for MPC in Matlab.

RESULTS The current control strategy, in contrast to the proposed MPC, does not predict future changes of the system. Hence control decisions are made shortly after the system faces new conditions, which results in overreaction of the control system and waste of energy. MPC, however, can foresee these changes and come to wise control decisions before the system is confronted with new conditions. In our study, the prediction horizon of MPC is considered to be 9 hours and the first results show ca. 31%-43% reduction in energy use after implementation of MPC.

CONCLUSION In summary, we have introduced a model predictive controller for an office building. The advantage of MPC over a conventional controller is prediction of disturbance load to the building, which is obtained from weather forecast and occupancy schedules of the building. This results in optimal control inputs and less energy consumption compared to the conventional controllers. Finally, we achieved about 31%-43% reduction in overall energy use by replacing the current controller with a model predictive controller, while comfort parameters were also kept within an acceptable range.

ABSTRACT. The change from fossil energy generation to an energy system mainly based on renewable energy sources requires innovative methods how energy is produced and consumed. Especially the increasing percentage of fluctuating energy sources, like wind and solar power, will lead to a rising unbalance between energy generation and energy consumption. For the grid stability a balance between generation and consumption has to be maintained all the time. Due to the high costs for storing electrical energy flexible power plants or pumped-storage power plants assume this function today. In the future the number of those controllable power plants will decline and the operation hours will decrease as well. High generation costs will be the consequence and the number of flexible power plants should be as low as possible. Flexible electricity consumers are able to reduce the need for such backup power plants and lead to a more energy and cost efficient electricity system. Ventilation systems and chillers are widely spread in buildings and provide several degrees of freedom for flexible operation. For example floating set points for room temperature and air quality allow influencing the energy consumption of building ventilation systems. Thermal energy storages in combination with compression chillers and heat pumps also provide load shifting potentials without directly influencing the building climate.

In order to utilize those potentials a predictive control strategy for an air conditioning system has been developed and prototypically implemented in a hardware-in-the-loop demonstrator. Models for the building envelope, the ventilation system, the chiller and a cold storage are implemented and enable a grid and user friendly operation of the air conditioning system. Using forecasts for weather, internal loads and electricity prices a genetic optimization algorithm determines the most cost efficient operation strategy (e.g. for the upcoming day). Assuming that the electricity price is indirectly proportional to the current energy generation, the control strategy supports the integration of fluctuating renewable energy sources into the grid. To ensure that the predicted energy consumption is fulfilled during operation, an online load matching is required. Possible reasons for deviations between the predicted and occurring power consumption are incorrect forecasts as well as inaccuracies in the models. For testing the online load matching, the demonstrator is used. It consists of a programmable logic controller coupled with the thermal building simulation TRNSYS. The demonstrator enables to manipulate the weather or internal load forecasts. Like this deviation can be generated deliberately and the functionality of the online load matching can be tested.

In conclusion, a model predictive control for HVAC systems (air conditioning, chiller, storage) can support the integration of fluctuating renewable energy systems as well as to guarantee the comfort in buildings. Thermal storages increase the flexibility of the system and reduce the impact of load management actions on the building occupants. Due to uncertainties in forecasting an online load matching is necessary to ensure the promised load profile.

ABSTRACT. Real-time optimal control of heating, ventilation and air-conditioning (HVAC) systems needs to regularly reset the set points of the local control loops that have a significant influence on the energy performance of the whole system. However, resetting a set-point for a local control loop introduces disturbance within the control loop, as well as disturbance in other local control loops that interacts with this loop, which may significantly affect the stability of the system operation. Traditional reset methods follow a step or a rate-limited change. The former method has been found impractical as a step change, especially when the magnitude is large, will introduce significant disturbance into the whole system; while the latter method can overcome this problem, but the rate is always predefined using a rule of thumb and lacks a systematic and scientific study.

In order to identify a better way to reset the set-points (other than step or rate-limited change), it is necessary to build disturbance models which are able to describe the transient behaviors of the affected control loops triggered by resetting the set-points. To study transient behavior of dynamic system due to resetting of decision variables, disturbance models are developed with a subspace identification method (SIM) using canonical variant analysis (CVA) approach. The SIM is a black box system identification technique that has tendency to model SIMO systems without structural parameterization. Because of its intelligibility and intrinsic capability it can be used in the synthesis of model based optimization techniques. Data for training of SIM disturbance model is generated form HVAC test bed build in TRNSYS simulation environment. Step reset is introduced in chilled water set point temperature (classic finite step response method) and the tracking errors (disturbance) introduced in the control loops for the decision variables were recorded until the whole system settled. Next, the recorded data (input: reset in chilled water set point temperature and output: disturbance introduced in control loops) is used as training data (data-driven), to identify state space parameters {A, B, C, D ,K} for SIM disturbance model (SIMO).

Comparative analysis of developed disturbance model with respect to the process data (from test bed) was conducted, which demonstrated fairly good performance of the identified models based on accuracy. Since it is numerically stable and simple, this approach can be adopted easily for process industry. In the future work, a better way to reset set-points with the help of identified disturbance model will be developed, which can be used to reduce the disturbances in the local control loops due to set-point reset and hence to enhance the stability of overall system.

ABSTRACT. INTRODUCTION In this paper, predictive cold storage management control algorithms for stratified cold water storages and their practical application in a demonstrator building are presented. The demonstrator building Energy Efficiency Center (www.energy-efficiency-center.de) is a research building in Würzburg, Germany, that implements novel, innovative and energy efficient materials, systems, and technologies, exemplarily demonstrating their applicability.

METHODS A generic algorithm for the management of stratified thermal water storage tanks in buildings based on model predictive control (MPC) is investigated that can be used independently of the building’s heat/cold generation, consumption and consumption control. The main components of the considered storage management are the short term load forecasting of the heat/cold consumer(s) using weather forecast, the MPC algorithm using a bilinear dynamic model of the stratified storage and operating modes of the heat/cold generator(s), modeled as static operating points. The MPC algorithm chooses between these operating modes to satisfy the predicted cold demand with minimal costs.

RESULTS and DISCUSSION In the demonstrator building, two cold storage management systems are available: A novel passive infrared night cooling system and a conventional system consisting of a chiller and recooling unit. For both systems, the predictive cold storage management control is applied both in simulation and in the demonstrator building. Its performance is compared to the performance of typical conventional non-predictive control. Simulation results show the superior performance of the predictive solution, while measurement results proof practical applicability of the predictive cold storage management solution.

CONCLUSIONS Feasibility of the presented approach for predictive cold storage management was successfully demonstrated both in simulation and practical application in a demonstrator building. In an ideal setting, it can significantly increase performance of a storage system compared to typical conventional control. Compared to other MPC based approaches, the presented approach is promising for practical use because of its independence from the heat/cold consumer’s type and control and because it requires limited information and instrumentation on the plant. While additional costs for control equipment is low, engineering effort for the predictive MPC based solution is still higher than for typical conventional control since the model of MPC has to be adapted individually to each system. However, this effort can be lowered on the one hand by using existing model components and on the other hand by automatically determine (some of the) model parameters.

ABSTRACT. Model Predictive Control (MPC) of building systems is a promising approach to optimize building energy performance. In contrast to traditional control strategies which are reactive in nature, MPC optimizes the utilization of resources based on the predicted effects. It has been shown that energy savings potential of this technique can reach up to 40% compared to conventional control strategies depending on the particular building type. However, the effort needed to implement MPC in buildings is significant and often considered prohibitive. That is why until now fully-functional MPC has been implemented only in few buildings. The following difficulties hinder the widespread usage of MPC: (1) significant model development time, (2) limited portability of models, (3) model computational demand. In the present study a new model development framework for an MPC system based on a Genetic Algorithm (GA) optimization is proposed. The framework is intended to allow easy model adaptation for new buildings and fast simulations to meet the strict performance requirements of the GA optimization approach. This is achieved by the introduction of the generic zone model concept and the implementation of the Functional Mock-Up Interface, which is used to link the models with the MPC system. The framework was used to develop and run initial thermal and CO2 models. Their performance and the implementation procedure are discussed in the present paper. The framework is going to be implemented in the MPC system planned to be deployed in chosen public and commercial buildings in Denmark and United States.

ABSTRACT. After the Paris climate pact was adopted in December 2015, policies of all countries will increasingly aim to curb CO2 emission levels. Policies translated into legislation, and various market support schemes will influence choices made by designers, contractors and building owners. Based on research carried out by BSRIA, this paper argues that it is time all stakeholders in the process of building construction, including policy makers, manufacturers, architects, contractors and end users, forge an holistic response to solving the problems of under-performing building. Product-only related approaches, adopted by many countries do not always deliver durable performance improvements, nor raise the overall efficiency of a building. The trends towards integrating renewable energy systems tends to increase metering and controls, and consequently a high level of system complexity.. For such systems to deliver the promise of lower CO2 emissions and a lean and energy efficient operation, a much higher level of knowledge, awareness and cooperation is necessary among all project stakeholders. This presentation will aim to identify the components of the closer relationships between environmental goals, market dynamics and stakeholder attitudes.

ABSTRACT. In the upcoming years, the energy requirements for buildings will have an ascending tendency regarding low energy consumption, primary reduction in greenhouse gases (CO2), increase of renewable energy sources and overall reduction of peak loads. Main goal of project SWIVT (www.swivt.tu-darmstadt.de) is to enhance, rebuild and optimize energy consumption in an existing settlement located in the city of Darmstadt by connecting several separate buildings into one energetic unity. In that sense, a new building block will be introduced into existing quarter state as an entity which can in time intelligently share its energy surplus with other buildings by means of integrated energy storage system. So that the energy balance in every time step between buildings and network will be improved. To ensure this kind of system with the means of smart energy optimization, there is a need to connect every component of the system and think of a plausible solution of running the system. Optimization for our system is conducted with the means of linear and mixed integer linear programming and the goal of the optimization is to ensure and cover the heat demand of the consumers on the one, and to gain profit on the other hand. Goal function is then guided by minimizing the money losses and to ensure that, for each time step, the gas and electricity prices from Entega Energie GmbH (Electricity and gas provider) are monitored. Optimization had been conducted for 4 scenarios in the project depending on the various heat sources, heat and power storage technologies and state of buildings. In order to work, every optimization method must have its own goal function which in our case is profit based. For covering the heat demand in the microgrid, a CHP system or heat pump are used in a combination with auxiliary heater and heat storage. So, in the case when there is no heat storage, CHP unit is necessarily working in the regime of covering the current heat demand, without the ability of adapting its heat production to the gas and electricity prices. As for the electricity demand, heat storage and auxiliary heater are represented as power storage and power grid, respectively. Computation is conducted with Simplex method of optimization and for the mixed integer problems the algorithm of Branch & Bound is used. Proposed model is searching for the current electricity prices and on price based assumptions it makes a decision, i.e. it is not a predictive model. The goal of running the system is maximization of profit throughout the observable period. The optimization goal can be described by the following goal function formulated in the way that it enables the CHP system to work on its maximal power which is bigger than the current heat load, thus the energy surplus can be stored for periods when market conditions aren’t favorable for CHP system to work.

ABSTRACT. The purpose of this study is to estimate energy saving potentials of desiccant-enhanced evaporative (DEVap) cooling system with district heat source based on a combined heat and power (CHP) system. The DEVap cooling system is an alternative to vapor compression system. A DEVap cooler is comprised of an internally cooled liquid desiccant dehumidifier and dew point evaporative cooler. The DEVap cooler is possible to operate the two devices independently. The liquid desiccant unit of the DEVap requires heat source in the process of regenerating diluted liquid desiccant solution. For that reason the DEVap, thermally driven cooling system, has an advantage of using heat energy in cooling season. In this study, district heat source based on the CHP system is applied to the DEVap as a heat source and cooling coil and terminal reheating coil is installed auxiliarily to meet supply air temperature set point. Supply air flow rate is modulated according to cooling demand as a variable air volume (VAV) system. This study compared energy consumption of the VAV air conditioner based on absorption chiller with the DEVap air conditioner to evaluate energy saving potentials of the DEVap. The absorption chiller is also thermally driven cooling system unlike electric chiller. A simulation is conducted during cooling season that performance of cooling system is expected to show biggest difference. The result of this study is predicted the DEVap cooling system with district heat source saves energy compared to the VAV sysem with district heat source in the cooling season.

ABSTRACT. The aim of this research is to propose a simplified prediction model for liquid desiccant system performance in hot and humid climates. The liquid desiccant pilot system used in this research was designed 2000m3/h process air and 35kw air-cooled chiller provides cooling water at any given temperature. The lithium-chloride (LiCl) solution is used as the liquid desiccant. From the experiment results, it was found that the experiment data collected from the liquid desiccant pilot system operation. The measurement of dehumidification performance values are conducted during the summer in Seoul, South Korea when the outdoor air (i.e. process air) is hot and humid. The liquid desiccant system performance data was statistically analyzed using the response surface methodology (RSM). The impact of each operation parameters on the liquid desiccant system performance were estimated by analysis of variance provided from Design expert 9.0 tool. After that the analyzing process, the simplified linear prediction model was derived as a function of six operation parameters, such as air mass flow rate, solution mass flow rate, ambient air dry-bulb temperature, ambient air humidity ratio, solution inlet temperature and solution concentration, have significant impact on the system performance. Finally, to verify the reliability of the proposed model, a comparison of the response values predicted by the proposed model and the experimental data. The proposed model predictions are within 10% of the experimental values.

ABSTRACT. Introduction : Even if nZEB reached, we found out that performance of VRF in buildings is lower than assessed during the design phase. Also related comfort, improvements are to be done. By monitoring VRF systems in buildings we found that the energy performance and comfort reduces by increased oversizing of the equipment to the building load. By design it is difficult to assess the real building load correctly because of the uncertainty of many parameters. In the past, after designing the installation, the equipment was installed and that was also the end of the process, there was no verification of the result. Now, with new technologies, we can verify the result of the process of design – installation – commissioning and feedback to the design of the (refurbishment) equipment. In our research we have defined the real building load by monitoring the VRF system and by analysis of the data we can optimise the selection of the VRF. As a result we can increase energy performance and comfort of the VRF system in the building to its potential. Methods : For determination of cooling and heating capacity of the VRF system we used the compressor curve method, which requires no measuring equipment but can calculate the performance by using just the sensors and operational data of the unit. Results: Most VRF systems in buildings are oversized and thus operate at less than optimal performance. By monitoring and analysing the data we can define the amount of oversizing and select an optimal unit for refurbishment. Discussion: Compliance with (national) legislations, prepare for climate change Conclusions: In order to reach optimal energy performance and comfort in buildings, it is important to adequately size the capacity of the equipment to the building load and monitor the equipment after commissioning, so that fine-tuning can be done.

ABSTRACT. Introduction : VRF systems in commercial buildings are mostly operated under less than 50% heat load conditions through a year. Therefore it is important to improve its performance under low and middle heat load condition. For this purpose, an innovative energy-saving A/C controller and a new compressor were developed in order to enable an optimum operation under low and middle heat load conditions in buildings. These technologies were applied to new developed VRFs “VRV X” and these new VRF products have been launched since March, 2015 in Japan. This report shows the annual average COP and annual energy consumption of the new VRFs in comparison with those of the conventional VRFs.

Methods : In the new A/C controller, capacities of indoor units are optimized by the combination of the real-time prediction of the indoor heat load and the capacity characteristics of the heat exchanger of the indoor units. For examination of annual average COP and annual energy consumption of VRF systems, we conducted the partial heat load performance tests in the test facility in Chubu Electric Power under some real operating conditions in the real building. The performances of the conventional VRFs and the new ones were measured at 37 points in cooling operations and 31 points in heating operations by the air enthalpy method. And the annual average COPs of these VRFs were predicted by combining the COPs of the VRFs obtained by those tests and the annual variations of operating conditions, i.e., heat load and outdoor air temperature, in the real building.

Results and Discussion: The rated COP of “VRV X” was slightly higher than the conventional VRF, but in the lower heat load conditions, the COPs of “VRV X” were much higher than the conventional one. In the conventional VRF operation, the compressor repeated start-up/shutdown operations, and then the COP got worse under low heat load conditions. In “VRV X” operation, on the other hand, the compressor speed was kept almost constant, and COP got higher in comparison with the conventional one. It was demonstrated that the annual average COP of “VRV X” increased by 40.6% and the annual energy consumption was reduced by 28.9 % from the conventional one in the model office building.

Conclusions: We developed an innovative energy-saving A/C controller and a new compressor in order to enable an optimum operation under low and middle heat load conditions in buildings, and they were applied to new developed VRF products “VRV X”. We compared the performance of “VRV X” and a conventional VRF by the part-load performance tests in the test facility. It was demonstrated that the annual energy consumption of “VRV X” was remarkably reduced from the conventional VRFs.

ABSTRACT. Conventional design of chiller plant is typically based on the peak cooling loads of buildings, while the cooling load reaches its peak level for only a small proportion of time in a year. This results in the oversizing of chiller plant and thus causes significant energy wastes. In this paper, a robust optimal design based on performance evaluation is proposed to optimize the design of chiller plant concerning impacts of uncertainty in the design input data and the system reliability in operation. Monte Carlo simulation is used to generate the cooling load distribution and Markov method is used to obtain the probability distribution of system state. A case study of a building in Hong Kong is conducted to demonstrate the design process and validate the robust optimal design method. Comparisons are made among conventional design, uncertainty-based optimal design and robust optimal design. The results show that the system could operate at a relatively high efficiency and the minimum annual total cost (including annual operational cost, annual capital cost and annual penalty cost) could be achieved under various possible cooling load conditions considering the uncertainties and system reliability.

ABSTRACT. Primary-secondary pumping system is widely utilised in the Heating, Ventilating, and Air Conditioning industry. This type of system has an energy saving potential over the constant speed primary pumping system. However, the system uses a surplus amount of energy that can be saved, the low delta T syndrome and low pumping efficiency are the main energy wasting reasons. The implementation of a proper design and novel control strategy can eliminate these two problems, knowing that the design of the bypass (decoupler bridge) is still a topic of debate. Thus, the focus in this paper will be enhancing the design and control of the bypass, developing an energy efficient control for the secondary loop including the pumps and the two way control valves, and setting an energy efficient sequencing of operation for the primary and secondary pumps. Calculating the bypass pipe diameter and its control strategy are often estimated according to the designer experience, rather than a code of practice, the goal for this paper is setting a guide for the bypass design. An analytical approach is used to find the most efficient design, where the model simulates the water distribution loop, pumps, chillers and control valves. Pressure drop in the system is categorised into three types; speed dependent, pipes, and controlling pressure drops. Pumps are modelled by curve fitting to real pump performance curves. Control valves are modelled with their non-linear flow characteristics. While the control scheme is applied as the signal given to the variable frequency drive on the secondary pump. The model is built to simulate chilled water system. Results are acquired from several schemes, having different number of load terminals, each having its separate control valve, each system has its constant speed primary pumps, where one pump is installed for each chiller, and a variable speed secondary pumps set are chosen according to each system. The various configurations for both bypass and secondary pump control are implemented on this model, in order to demonstrate the energy savings, and also testing the performance of each system showing its effect on the heat loads. The results show that some modifications to the design can save a considerable amount of energy compared to the conventional design. As a conclusion a design guideline is suggested in this paper for an energy efficient bypass pipe.

ABSTRACT. The changing climate and the increasing density of technical equipment in office buildings lead to an increasing demand of cooling to maintain a healthy and comfortable indoor environment. The number of options to provide cooling in building practice are limited and make traditionally use of technologies which convert high exergy electrical energy into low exergy thermal energy for cooling, such as compression chillers.

Technologies which make use of renewable energy sources such as absorption chillers powered by waste heat or solar energy are due to their technological complexity still not fully accepted. An alternative concept for providing cooling based on solar energy is the application of thermo-acoustic heatpumps

Thermo-acoustic engines are heat engines which convert heat into acoustic power and subsequently into energy in the form of electricity, heat or coolth. The well accepted advantage of thermos-acoustic engines is the simplicity of its mechanical buildup, characterized by no moving parts. Another advantage is the instantaneous conversion providing cooling when the sun shines. Thermo-acoustic engines are reported to have been successfully applied in space exploration and on naval vessels. However, limited knowledge is available with regards to its applicability for serving building conditioning systems.

The research questions to be answered by this contribution are: 1. Which modelling tools are available to predict the building integrated performance of thermos-acoustic heat pumps? 2. Which control strategies are feasible to modulate the supply of cooling accordance to the buildings load profile and to maximize the systems efficiency? 3. Which modelling abstraction level is required to satisfactory represent the system performance for conceptual building and system design?

To answer the research questions three methods are applied: (1) literature and software survey; (2) Thermo-acoustic heat pump modelling ad (3) performance evaluation of an building integrated thermo-acoustic cooler.

First results from the literature survey indicate a great variety of modeling approaches being applied to model thermos-acoustic heat engines. The modelling approaches range from electric resistance analogy models based on fixed performance efficiencies up to models to numerically integrate one-dimensional wave equations. The case study used for the analysis shows representative cooling load profiles for low-energy office buildings in The Netherlands. However, the mass of the building is expected to reduce the efficiency of the direct acting cooling system.

The adaptive efficiency based modelling approach chosen for the thermos-acoustic heat pump is capable to provide a first indicative estimation of the integrated performance of building and cooling system. However, the model needs to be detailed with respect to its dynamic conversion characteristics under conditions different to peak load conditions to generate results which compare with measurement data.

ABSTRACT. Small-scale on/off chiller integrated air-conditioning (AC) system is wildly used for cooling buildings. In this AC system, the on/off operation of the chiller introduces significant disturbances on the control loop of the AC system and deteriorates the performance of the space temperature control especially when the on/off switch is frequent. For the on/off controlled chiller, another issue is that the frequent switch speeds up the wear and aging of the chiller. This paper presents a bilinear control algorithm to improve the robustness of the space temperature control. A water tank is designed in the water system for further enhancing the system performance. The bilinear control algorithm was validated in a simulation A/C system as well as on an experimental platform. The validation results show that the bilinear control achieves better space temperature control performance than conventional PID control does when the chiller is switched on/off frequently both in the virtual AC system and the real experiment system. The control performance is tested in the simulation AC system when the water tank is introduced. The results show that the optimal water tank size can guarantee the allowed on/off frequency of the chiller very well and simultaneously enhance the space temperature control performance efficiently. The proposed method has the potential to be applied in real on/off chiller integrated AC systems for improving the robustness of space temperature control and reducing the on/off frequency of chillers simultaneously.

ABSTRACT. Climate change and increase in energy cost have motivated industries and research leaders to focus on renewable energy and energy efficiency. Buildings are the major electricity consuming element for urbanized cities. Under a subtropical climate, air-conditioning and especially the cooling system demands the most energy, representing about 30 – 40% of a typical commercial building’s electricity consumption. The major part of a cooling system, the vapor compression chiller (VCC) operates under a Carnot vapor refrigeration cycle, utilizing ozone depleting refrigerants. If released into the atmosphere, these refrigerants significantly contribute towards global warming.

The adsorption cooling system is a good alternative to replace the VCC because of its environmental friendliness (no refrigerants), energy saving potential (no compressors), no moving parts and, lower vibration and noise levels. The working principle of adsorption cooling systems is to maintain a low pressure condition in a closed loop by adsorption. Thus, the adsorbate can evaporate in an evaporator, removing heat from the environment. An adsorbent packed in an adsorber will adsorb the vaporized adsorbate, maintaining a low pressure. The adsorbent will eventually be saturated with the adsorbed adsorbate. Then, heat from solar or waste heat sources can be supplied to the adsorbent to desorb the adsorbate, completing the whole thermodynamic cycle.

Today, however, VCC still dominates most applications, since adsorption cooling systems have a lower specific cooling power (SCP), leading to a bulky system. In this study, an adsorption cooling system with a composite material (zeolite 13X/CaCl2) as the adsorbent and water as the adsorbate has been built and the system performance is studied experimentally under various working conditions. The adsorption cooling system consists of two adsorbers using heat exchangers as the adsorbent bed, an evaporator (chilled water tank), a condenser, separate heating and cooling water tanks, and is equipped with measuring instruments and supplementary system components. Under the standard operating condition: adsorber cooling water inlet temperature of 28 °C, desorption temperature of 85 °C, chilled water inlet temperature of 14 °C and adsorption/desorption phase time of 8 minutes, the SCP recorded is about 376 W/kg, of which the cooling capacity is about 752 W (i.e. 2 kg of the zeolite 13X/CaCl2 composite adsorbent are utilized). Most importantly, it is found that a much lower desorption temperature can be utilized to desorb the composite adsorbent when compared with the pure zeolite 13X adsorbent. Its satisfactory performance suggests that this novel composite material has potential for use in adsorption cooling systems.

ABSTRACT. INTRODUCTION. One objective of the IEA EBC Annex 61 is to collect and analyze case studies of Deep Energy Retrofit DER) building projects. This effort has collected and analyzed information on 26 case studies from Europe and the US. The objectives were to: • Show a variety of successful DER projects to motivate decision makers and stimulate the market; • Collect and summarize information on energy efficiency measures used to achieve more than 50% site energy use reduction compared to prerenovation; • Learn the drivers for these projects and the business and financial strategies used to make these projects economically justifiable. METHODOLOGY. Data and analyses formed the basis for technical and business guides being developed within Annex 61. This paper presents the study methodology and results, which answer the following questions: • What was the primary reason for the renovation? • How much energy were used before the renovation and how much was saved? • What were co-benefits? • What energy saving technologies were implemented? • How were the DER projects financed? What business models were used? • What was the cost effectiveness of the projects? • What were the Lessons learned of interest to a broader audience? • What can be concluded for the modeling of future projects? • What can be concluded for the financial mechanisms and business models for future projects? RESULTS AND DISCUSSION. Often non-energy-related and energy-related reasons for building renovation are complementary; nevertheless, non-energy related reasons, like need to: repurpose building use, improve poor working conditions, improve poor architectural quality, and meet the general need for equipment replacement are often the main reasons for initiating the project. For most of the case studies, pre-renovation energy use intensity fell in the range of 200-400 kWh/m²/year; after DER, this was reduced to 50 to 100 kWh/m²/year. Energy savings were obtained by implementing bundles of energy-saving measures, including improvements to building envelopes and to technical systems. Resulting benefits included improved indoor environment quality and improved “green building image.” These DER projects were financed from different sources, from entirely self-financed projects including Energy Performance Contracting, to different types of regional, national, and even international support (i.e., from EU). The cost effectiveness of the projects increased when a major renovation cost were considered anyway and the DER was only adding on more ambitious energy targets than those from the building codes; so the pay back periods varied widely; from 11 years to more than 30 years. An important lesson learned was that user behavior plays a key role in the energy consumption, e.g. when heating consumption typically exceeds calculated levels. The use of user training programs and improved documentation for common IT control equipment significantly decreased energy consumption and Indoor comfort complaints. CONCLUSIONS. Collection and analysis of data pertaining to 26 Case studies under Annex 61 contributed significantly to the knowledge required to develop well-grounded technical and business Guides for Deep Energy Retrofit.

ABSTRACT. INTRODUCTION: Numerous pilot projects conducted worldwide have demonstrated that energy use in commercial and public buildings can been reduced by more than 50% after renovation. IEA ECBCS Annex 46 research has identified more than 400 energy efficiency measures that can be used when buildings are retrofitted. Such measures include those related to the building envelope, mechanical and lighting systems, energy generation and distribution, internal processes, etc. Implementation of some individual measures (e.g., building envelope insulation, improved airtightness, co-generation) can significantly reduce building heating and cooling loads or minimize energy waste, but require significant investments with long paybacks. However, when a limited number of “core technologies” are “bundled” and implemented together, they can significantly reduce energy use for a smaller investment and provide a faster payback. Characteristics of some of these core technology measures depend on the technologies available on an individual nation’s market, on the minimum requirements of national standards, and on economics. Additionally, requirements of building envelope-related technologies (e.g., insulation levels, windows, vapor and water barriers, etc.) depend on specific climate conditions. METHODOLOGY: The core bundle of technologies include building envelope insulation levels and window characteristics optimized by the Annex 61 modeling team, which is comprised of members from Austria, China, Denmark, Estonia, Germany, Latvia, Sweden, UK, and the United States, by computational simulation of representative buildings for different climate zones of the participating countries. The following four scenarios were modeled: (1) a baseline using a pre-1980 energy standard, (2) a base case based on major renovation following minimum current standard requirements, (3) a 50% site energy use reduction compared to the baseline, and (4) a current “national dream” scenario. RESULTS AND DISCUSSION: Modeling results show that it is possible to achieve a deep energy retrofit (DER) when the retrofit is combined with major renovation of buildings with low internal loads (e.g., office buildings, dormitories, barracks, and educational buildings). In hot climate zones with significant cooling needs, this task is more difficult and may require additional energy efficiency measures (e.g., reduction of plug loads, water conservation measures, advanced HVAC systems). DER is easier to achieve in heating-dominated climates and in cases where, either for cultural or normative reasons, cooling is not desired and building users can tolerate temporarily increases in indoor air temperature (e.g., up to 77 °F [25 °C]). CONCLUSION: To meet long term energy goals, major renovation of buildings must be combined with a DER that targets a reduction of at least 50% of building site energy use. This reduction in energy use can be achieved by implementing a limited number of market-ready core technologies bundled together. The key to making a DER cost effective is to time the retrofit as part of a major building renovation that already has allocated funds including those required to meet minimum energy requirements.

ABSTRACT. INTRODUCTION Denmark is participating in IEA Annex 61 “Development and demonstration of concepts for deep energy retrofit in government/public buildings”. The purpose of the Annex is to improve the decision-making process to achieve deep energy retrofits of government/public buildings, starting with the determination of working bundles of technologies and corresponding business models using combined public and private funding.

Denmark will contribute to the project with several buildings that serve as case-studies. One of these is a multi-storey office building from 1938. The building has undergone a comprehensive energy retrofit and the overall purpose was to reduce the energy consumption to a level corresponding to the requirements for the German Passiv Haus standard.

METHODS This paper describes the energy renovation carried out for the office building along with the calculations performed to predict the energy savings. The details of the analysis and the process of calibrating the calculation model to perform as the building are also described.

RESULTS The comprehensive energy renovation of the office building included:

• 300 – 430 mm exterior insulation on walls • 260 – 290 mm exterior insulation on basement walls • New triple-glazed windows • New insulation of domestic hot water installation • Improved air tightness (to meet the Passiv Haus requirement of 0.6 l/s per m2 at 50 Pa) • Two new separate ventilation systems (offices and meeting rooms) with heat recovery • Pre-heating of ventilation air using horizontal ground collectors and vertical wells • New LED lighting system in corridors and offices. • Automatic exterior solar shading on the facades to the southeast and southwest • 35 m2 solar collector on the roof connected to a storage tank

Based on the initial calculations it was expected that the heating energy consumption after the energy retrofit would be 82.6 MWh, i.e. corresponding to 15 kWh/m2 as required by the Passiv Haus definition. However, measurements showed a heating energy consumption of 258.9 MWh. DISCUSSION This discrepancy between measured and calculated results initiated a comprehensive analysis of the building energy consumption before and after retrofit in order to determine why the model did not deliver results similar to the measured data. A meticulous examination of the building and in particular the HVAC systems were carried out and based on this the calculation model was adjusted. After several iterations the model finally performed similarly to the building.

CONCLUSIONS It is possible to model and calculate the energy savings of buildings undergoing comprehensive retrofitting even when the buildings utilize quite complex heating, ventilation and air conditioning systems. However, in order to do so it is necessary to obtain very detailed information on all aspects of the building before and after retrofit. The less information available the more difficult it is to predict the expected energy savings and the consumption.

Even relatively simple calculation tools, e.g. Be10 and PHPP will be able to produce quite accurate results; however the input data needs to be thoroughly qualified.

ABSTRACT. INTRODUCTION: One of the critical tasks of the International Energy Agency’s Energy Conservation in Buildings and Communities Program’s (IEC ECBC’s) Annex 61 “Business and Technical Concepts for Deep Energy Retrofit (DER) of Public Buildings” is to develop bundles of core technologies (measures), which, when applied in major renovation projects to older (i.e., pre-1980) buildings, allow site energy reduction by 50% or better compared to the pre-renovation baseline. METHODOLOGY: A short list of these technologies was generated through analysis of DER projects. Characteristics of some of these “core technologies” depend on technologies available on an individual nation’s market, minimum requirements of national standards, and Life Cycle Cost (LCC) analysis. In addition to these factors, requirements for building envelope-related technologies (e.g., insulation levels, windows), depend on specific climate conditions. RESULTS AND DISCUSSION: This paper presents the results of a computational modeling analysis conducted by the U.S. Army Engineer Research and Development Center team to determine the performance potential of the core technologies for two types of buildings: Dining Facilities and Child Development Centers in 15 U.S. climates using the Net Zero Planner tool. This tool enabled simultaneous simulation of multiple building types and multiple technology bundles of energy efficiency measures in different climate zones. This research supported the development of requirements for building envelope characteristics, and of typical equipment best practices for DER projects. General guidelines for technology bundles to be used in DER projects were developed using information presented in this paper; combined with results of similar studies conducted and published by the IEA Annex 61 team members from Denmark, Estonia, Austria, Germany, Latvia, China, and the UK; and with previously published research by the paper’s authors on two other building types with a low internal loads (i.e., barracks and office buildings) for their respective nation-specific climate conditions. CONCLUSION: Results of these studies show that, unlike the buildings with low internal loads modeled previously, 50% of site energy use reduction cannot be achieved in most climate conditions using the bundles of core technologies previously considered. In general, it is easier to reduce energy consumption in heating dominated climates than in climates requiring cooling and humidity control. However, under specific climate conditions, the implementation of additional energy efficiency technologies and measures specific to building type and use, combined with a reduction of internal loads, can further reduce a building’s energy use intensity to achieve or even exceed the 50% reduction (i.e., by meeting the passive house or Net Zero Energy standard).

ABSTRACT. During the last few decades an increased attention has been directed towards reduction of building energy use. Results from numerous studies conducted all over the world show great potential in achieving energy savings of 50% and even more after renovation of residential and public buildings. In these studies hundreds of individual energy efficiency measures were identified attributable to e.g. building envelope, HVAC systems, energy production and generation systems, building internal processes including occupant behaviour. Bundling of individual measures together can greatly reduce energy use for a smaller investment, leading to a shorter payback time. This was indicated in a study of Annex 61 ”Business and Technical Concepts for Deep Energy Retrofit of Public Buildings” of program “Energy Conservation in Buildings and Communities” by International Energy Agency. This paper presents results of a simulation study to achieve deep energy retrofit (DER) in a Latvian public building. Simulation was carried out within the framework of Annex 61. The modelling project was a five story dormitory building (heated net floor area of about 3400 sq.m), located in Riga, Latvia (climate zone 6a). The building was composed of precast concrete panels that were typical building construction system in Latvia during 60’s and 70’s. A software “Riuska” was used for comfort and energy simulation. Following scenarios and assumptions have been used in modelling: Scenario 1 (baseline) represents the pre-1980 standard to describe the building envelope and systems before renovation. Scenario 2 (base case) is the country specific “business as usual” retrofit to meet requirements of minimum current national standards. Scenario 3 is related to application of core energy technology bundles to achieve approximately 50% energy use reduction against the baseline (scenario 1). Scenario 4 targets to achieve a current national “dream energy standard” (nZEB). Building use and systems operation schedules as well as use of appliances have been kept the same for all scenarios. Energy improvement measures for scenarios 2 to 4 focused mainly on the reduction of transmission and infiltration losses through insulation of building envelope and replacement of windows. These measures are one of the most frequently implemented ones in Latvian public buildings, since most of energy in Latvian buildings is used for heating (3451 heating degree days at base temperature of +17°C). Building’s energy need for space heating was 143 kWh/(sq.m·a) before renovation as for scenario 1 (pre-1980 standard) and has been reduced in the scenario 4 (dream energy scenario) to 27 kWh/(sq.m·a), achieving the national nZEB requirement.

ABSTRACT. The International Energy Agency’s Energy in Buildings and Communities Programme Annex 61 “Business and Technical Concepts for Deep Energy Retrofit (DER) of Public Buildings” aims at developing financially and technically feasible deep energy retrofit concepts. These concepts should consist of bundles of core technologies, which when applied in major renovations of pre 1980 buildings should yield a site energy reduction by 50% or more. The individual technological solutions to achieve this depend on national conditions such as building standards, general building practices and most importantly the climatic conditions. Retrofit solutions can be classified into three different renovation scenarios: Minor retrofit in order to achieve the national standard, major retrofit to achieve 50% reduction and advanced level retrofit to go beyond 50%. Many different studies show that individual renovation measures are economically feasible and environmental beneficial. However, when combined in deep energy retrofit bundles, certain technologies influence each other both environmentally and economically due to the interconnection in buildings. This paper demonstrates results from a simulation study of different retrofit technologies for a multi-family house in Sweden. Technologies are assessed both individually and as part of technology bundles. The analysis highlights the differences in the impact of individual technologies compared to the application in technology bundles. We thereby demonstrate the links between different technologies in deep energy retrofit concepts. We conclude that such effects need to be taken into account when designing retrofit concepts and call for optimized approaches according to climatic, environmental and economic conditions.

ABSTRACT. Designing zero-energy buildings (ZEB) is a complex but not an impossible task, which has also been illustrated through demonstration projects, including houses that produce as much energy as they use on a yearly basis. Over the last years an increased interest for ZEBs is also seen in practice, however, designing ZEBs is still challenging. In order to gain further currency, we need to collect new knowledge and communicate it in an easy applicable way for the building industry. This paper presents the development and objectives of a publication entitled “Zero Energy Buildings – Design Principles and Built Examples for Detached Houses” with a long-term perspective heading towards 2035 building design and targeting practicing architects and engineers as well as developers. The publication introduces a number of design strategies and technologies which are particularly important for the development of zero energy houses, and identifies technical and architectural potentials and challenges related to the application of these. The publication argues that the key issue is to design the buildings through a cross-disciplinary approach to architecture and based on an integrated design process. The project is part of the Danish Strategic Research Centre for Zero Energy Buildings at Aalborg University, Denmark.

ABSTRACT. Efficient operation of environmental control systems in buildings is not a trivial task. Insufficient coordination of processes in one domain (e.g. thermal control system) with other domains (e.g. visual control system) may result in inefficiencies. Moreover, the communication and as a result the collaboration between architects and service engineers in the design process is rarely optimal. Primarily building designers' knowledge of building systems is frequently wanting. On the other hand, building service engineers often work without explicitly reasoned procedures in determination the type, number, configuration, and placement of technical devices.

This paper reports on two related efforts. The first involves an experiment for testing the usability of a method to generate a schema for the distribution of control logic of buildings’ technical systems (heating, cooling, lighting, and ventilation). This method has the potential to support primary building designers in understanding buildings’ technical systems and can improve communication between architects and engineers. Furthermore, it facilitates the determination of the number and position of environmental control devices and helps in encapsulating control-related processes toward integrated systems operation. The usability of this method is currently being tested. In an initial evaluation phase, architecture and engineering students applied the method to existing architectural spaces. The second effort involves interviews with experienced professionals in both architecture and engineering fields to obtain specific feedback concerning the potential of the method for the automated generation of building control schemas. Moreover the professionals interviewed provided insights regarding their educational and professional background. This input not only sheds light on the improvement possibilities of the integrated design of buildings' technical systems, but can also support the refinement of the aforementioned schema.

The students' evaluation suggested that the proposed schema and its generation method were useful in improving the communication between architects and engineers and supporting the understanding of the buildings’ technical systems. Professional architects' impression of the method was largely positive too, however building service engineers emphasized the importance of timely and close collaboration between architects and engineers. Interview results suggest that architects receive in their education insufficient instruction regarding building systems. On the other side, none of the interviewed engineers had gained in their education any explicit knowledge of architects' working style and design attitudes. Moreover, inefficiencies in the collaboration between architects and engineers is recognized by both groups. The bulk of thinking regarding the nature and configuration of the technical systems begins only after the primary building design is already finished. Moreover, building service engineers typically operate based on heuristic and experience, rather than formulating an explicit – computationally verified – rationale for the determination the type, number, configuration, and placement of technical devices.

ABSTRACT. Sustainability certification schemes experience grooving popularity. Only few years ago, Denmark got its own sustainability certification scheme based on the German DGNB certification scheme run by Green Building Council Denmark [1]. The objective of this study is to investigate if and in what way a DGNB-certification scheme will affect the decision-making and design process. The study takes point of departure in four Healthcare Centres, all DGNB silver certified – A case study design, using semi-structured interviews. The results show that it is important to collaborate in the design team from the beginning also with the DGNB consultant and create commitment to the project. Additionally, the research show that in some cases the architectural design have been taken too fare in the initial phases without analysing and documenting several sustainable parameters. It creates a “point of no return”, which means it is not possible to priorities the assessment points in the certifications scheme when needed. Therefore, the paper recommends firstly, more focus on the planning of future design processes using DGNB. Secondly, the paper suggests further research about how to improve and support the iterative design process in the initial design phases securing decision-making on sufficient level of knowledge.

ABSTRACT. Several certification systems have been established to evaluate the sustainability of real estate (BREEAM, LEED, DGNB, …). Furthermore, there are numerous systems for certifying building operation, whereby focus is placed on the respective aspects in building operation, e.g.: Process performance (energy management, DIN EN 50001), sustainability in FM (GEFMA 160), system performance (building automation, eubac). The focus of the Green Building Label for new buildings lies in evaluating the planning and construction. Here the goal is to realize sustainable real estate, but the building’s sustainability can only be proven under operation. Thus, the question is to what extent the indicators that are currently used ensure that the targeted building performance goals are actually achieved and documented in real building operation.

Monitoring key performance indicators (KPIs) by the means of building automation opens up performance evaluations of operational processes. This uncovers and visualises trends and is an indication of measures to improve the processes. Especially for energy management, several methods are described and standardised. Nevertheless, a holistic set of process performance indicators is not available today. Actually, a well-planned building and its certification will not ensure operational building performance. KPIs that would allow monitoring and ensuring the holistic quality of a building are neither defined nor agreed upon.

In this paper, we present a concept to extend existing green building certification schemes by adding criteria that focus on the performance of operational building processes (e.g., management of comfort and health performance, energy maintenance and asset management). Starting with a brief overview about today’s certification schemes, we show inconsistencies concerning planned and operational building performance in today´s certification schemes in general, as well as for a real and certified building. Main operational building processes in technical building management are described using business process oriented methods. The processes are analysed by reviewing existing criteria and their expressiveness in elicitation of their performance. Based on the analysis, a set of additional performance indicators (describing the provision of comfort and health performance management, energy management, maintenance management, asset management) are developed. By the means of building automation, we show the monitoring of the developed KPIs and their validation for the mentioned certified building. By mirroring existing certification criteria for green buildings with new developed KPIs, we develop a concept to extend existing certification schemes.

Main results of the paper are: • Determination of inconsistencies in certification schemes concerning planning and operational performance • Process-oriented description of operational building processes • Review of existing certification criteria and development of new key performance indicators for monitoring operational building performance by building automation measures • Concept for extending existing certification schemes by adding new criteria for certification of green buildings

ABSTRACT. INTRODUCTION This study is a part of a green settlement research project conducted by Istanbul Technical University and Ministry of Environment and Urbanization of Turkey. In Eskişehir, Turkey, a new settlement for 80,000 people is projected by green settlement principles for environment, social life and economical life. The research project aims to constitute a methodology for green settlement design projects in Turkey. As a part of the research project, the study which is summed in this abstract aims to reveal the potential of CO2 reductions accounted by buildings and to set the methodology of energy consumption and CO2 emissions calculations in a case settlement in Eskişehir, Turkey. METHODS As the research project cover all type of buildings in the case settlement, this study covers non-residential buildings as office, shopping center and industrial building. For each type of building a base building, a cost-optimum building and a nearly zero energy building are determined. Base buildings are designed by Turkish and International standards for building envelope, lighting systems and mechanical systems to represent generally each type of building. Cost-optimum and nearly zero energy buildings are determined by the methodology described in the EU Directive of Energy Performance of Buildings, 2010. Costs of each building type and costs of each building component which affects the building energy performance are determined by the data provided by the Ministry. Afterwards the results are evaluated by the data that is received from the urban planning team of the research project. By the number of each type of building in the settlement and total area, the CO2 reductions are calculated for cost optimum and nearly zero building cases. In the second phase of the study, each cases are connected to a district heating and cooling system and energy demand for heating and cooling for each building is calculated. Global cost calculations are also repeated for each case building. Finally the CO2 reductions are calculated for cost optimum and nearly zero energy building in the district heating and cooling system. RESULTS and DISCUSSION In the whole settlement, residential buildings consist of the majority of the building stock. However still, non-residential buildings have a big CO2 reduction potential as their energy consumption per unit area is high. Calculations showed that, in total, 35% of CO2 reductions by cost optimum buildings and 66% of CO2 reduction by nearly zero buildings can be obtained throughout the whole settlement. CONCLUSION The results showed that, a significant portion of energy consumption and CO2 emission reduction can be obtained by simple and low initial cost implementations in the buildings. Furthermore, compared to building stand-alone energy systems, district heating and cooling systems become more energy and global cost efficient. The calculations showed that although renewable energy systems are not feasible for base cases, they may even become cost-optimum cases for some building types. However, renewable energy system installations for whole settlement is become more energy and cost efficient compared to building integrated systems.

ABSTRACT. Our massive dependence on fossil fuels has upset the very climatic system that made human evolution possible. Energy efficient and low-carbon technologies will play a crucial role in the energy revolution needed to make this change happen. Biomass, hydropower, wind energy, solar thermal collectors, photovoltaics systems, centralized solar thermal power plants, solar architecture and geothermal energy and a number of experimental technologies are raring to go. A second basic requirement of such a fully renewable energy supply structure is the intelligent interchange of energy between regions. This interchange can be managed by the power grid, gas networks (using solar generated hydrogen) or by transporting biomass. As energy use is strongly linked to building age, there is enormous energy and CO2 savings potential in upgrading building envelopes and heating and cooling systems to modern standards. Recognising the importance of energy efficiency improvements in the buildings sector, the EU introduced the EPBD in 2002. In 2010, the EPBD was revised with tougher requirements for buildings, including the requirement for member states to ensure that all new buildings will be nearly zero-energy buildings (ZEBs) by the end of 2018 for buildings owned by public authorities and by the end of 2020 for all other new buildings. The transition to zero energy district will have positive benefits for other sectors, most notably the power sector, and will translate into avoided electrical capacity additions, as well as reduced distribution and transmission network expansion, with potentially huge savings for utilities. The goal of this research is to promote the use of active energy systems into high quality architecture and urban designs. To achieve this goal I defined architectural integration criteria per technology, highlighting on one hand the need of improving designers knowledge, and on the other hand the need of enhancing the building and urban integrability of the products available on the market. I have been focusing on the tools and methods available for the dimensioning and positioning of active energy systems in buildings and urban public spaces, showing that new, architects friendly, tools are urgently needed. Finally, I provided a wide selection of well documented case studies, demonstrating that energy efficient strategies on renewable sources can be the basis for inspiring high quality architectures (in new constructions and in building renovations and on experiments or prototypes or visions). Further the purpose of the research is the development of a open source database established to address these issues by presenting, on one hand, the active energy systems and innovative products available in the market today and, on the other hand, the information you need to optimally integrate them in the architecture of a building and built environment. By choosing a specific technology and an integration type (roof, façade, balcony…) the user gets access to a selection of appropriate products, presented in the form of synthetic A4 sheets. These sheets include architect oriented information, contact details and pictures, both on the product alone and situation examples in buildings.

ABSTRACT. INTRODUCTION The increasing complexity of these sustainable buildings requires a design team of architect and engineers already from the conceptual design phase. In this phase the highest impact of changes for the lowest costs can be achieved. The more a design is developed the harder (and more expensive) it becomes to make adjustments. In this case the design task was a nearly zero energy building to be realized in the Netherlands. It was a real setting in practice in which the researchers could organize a workshop during the conceptual design phase of the project. METHODS A new design approach during the conceptual phase which was chosen in this study is the integral design methodology which makes use of morphological charts and overviews. The workshop was organized for the team design members as well as the initiator’s of the project. The workshop started with a lecture about the integral Design method in the context of nZEB design. After this, a design session was done, an exercise session about a nearly zero office building located in Utrecht to make the members familiar with the method sothat they would be able to use it for the proposed new multifunctional nZEB building. RESULTS and DISCUSSION The particpants generated individual morphological charts and morphological overviews as a team. The schemes were analysed and also the interactions between the morphological charts and morphological overview were compared CONCLUSIONS Results showed that the morphological design methodology was a good way of showing the knowledge and influence of each design discipline/member. The design tool enabled an effective support for the design team during the conceptual design phase, but also to study the process within the design team and individual members in detail.

ABSTRACT. In Danish building code and many design briefings, criteria regarding thermal comfort are defined for “critical” rooms in residential buildings. Identifying the critical room is both difficult and time-consuming for large, multistory buildings. To reduce costs and time, such requirement often causes other less critical rooms to be designed with the same constraints as the critical one. In this paper, we propose a method to overcome the difficulty of identifying critical rooms and exploit the design potential of other rooms. First we have defined a set of typical room variations present in most residential buildings. For each room variation, we perform 100.000 simulations while varying important design inputs such as window-floor-ratio, ventilation rates, glazing properties, and shading properties. Prior to this, the Morris method was used to identify and fixate insignificant inputs. A simulation engine based on the hourly version of ISO 13790 is used to calculate the number of hours with unacceptable operative temperature. As a result, the design team can assess a large number of room variations and input configurations by filtering millions of pre-calculated simulations accessible through a web service. An interactive parallel coordinate plot helps the design team to filter the many simulations. Such analysis reveals favorable input spans and assists the design team to quickly assess various design choices.

ABSTRACT. The building’s performance-based design approach is most effective when applied at the initial stages of the design processes. This philosophy was gradually understood and accepted by building owners and ESD (Environmental Sustainability Design) consultants for commercial buildings. Particularly, design of a laboratory intensive building still poses a tremendous challenge since energy savings should only be pursued without compromising the user’s safety. This study will demonstrate the effectiveness of integrated performance-based approach to design a high-performance laboratory building in Singapore. To comply with Singapore’s GreenMark (building certification scheme), this project aims to achieve above and beyond GreenMark Platinum standard. To achieve this target, design charrette was conducted during the initial stages of the design to develop performance goals and to assess possible technology/system performance. Comprehensive modelling and simulation were conducted for this study aiming at maximizing energy efficiency, include (i) Computational Fluid Dynamics (CFD) for optimization natural ventilation design, (ii) daylighting and glare simulation for optimum natural daylighting throughout the building and (iii) energy modeling to estimate facility energy consumption and to develop energy-efficient measures. The use of these computerized simulation tools help to validate building system performance and to support decision-making for recommended strategies by establishing payback costing for each innovative technologies. In addition to the modelling and simulation process, metering studies were carried out to benchmark laboratory and office plug load. Measurement and verification studies were also conducted to establish energy savings through metering actual implementation device. With proposed strategies and technologies, the total building energy consumption is expected to reduce 44.12% yearly. From this study, an integrated performance-based design approach is proven to be most effective to explore the most energy efficient strategies and to design a high performance laboratory building. This study is also the first exemplary case study to demonstrate at least 40% energy savings for a laboratory intensive building in Singapore. It is hoped that this energy efficient measures and strategies from this study can be applied for other similar projects in future. Furthermore, the benchmarking and measurement practice can also provide solid evidence for simulation model input for a laboratory intensive building. Finally, this study could be a good reference for other building owners, developers, facility managers, architects and building engineers to design a high performance building.

ABSTRACT. In the present work a real dwelling (a semi-detached house in the Netherlands) has been modelled with an in-house modular object-oriented building simulation tool, called NEST-Buildings. This software models the whole building as a collection of elements (e.g., walls, rooms, outdoors, people, ventilation tubes and boxes, solar radiation distributor, HVAC, airflow, CO2 transport, etc.) connected between them through boundary conditions. New configurations can be easily handled by adding/removing elements. Furthermore, the building elements may be modelled with different physical models (ranging from global, 1D, 2D, 3D to CFD&HT models) enabling the modelling of complex systems with different levels of detail in the same simulation.

The main objective of the modelization of a real dwelling is to use it as a test bench of a new affordable, easy to use and apply, integral dwelling climate control system called DCCS (Dwelling Climate Control System), whose main objective are reducing the energy use of buildings by optimizing the parameters of the heating and ventilation system and ensuring the indoor quality inside the dwelling (by means of CO2 concentration control).

ABSTRACT. TEKNOsim is a well-established software tool for simulation of thermal indoor climate. It is used for modelling and simulation of thermal loads, indoor temperatures and thermal comfort. TEKNOsim 5, a new version of the simulation tool has been launched with several new features and enhanced functionalities. This paper presents results of testing and validation of TEKNOsim 5 against two state-of-the-art building energy simulation tools, IDA-ICE and DesignBuilder. Comparisons with the reference tools have been made for a number of test cases. Simulation results indicate that, for realistic scenarios, there exists a very close agreement between TEKNOsim and the reference tools. The largest discrepancies between the simulation tools are observed for unrealistic scenarios. Besides this, the observed trends in discrepancies between the tools also suggest that the algorithms used in TEKNOsim 5 are correct.

ABSTRACT. The energy demand of buildings has been already investigated in several projects, with particular reference to the energy demand for heating. When dealing with GSHP (Ground Source Heat Pumps) it is required not only the energy demand of the building, but also the energy profiles. Moreover the cooling of the buildings as well has to be defined. For promoting the diffusion of GSHP (Ground Source Heat Pumps) a tool for sizing these systems will be carried out in the H2020 research project named “Cheap GSHPs”. The paper presents the set up of a database with energy profile of a certain amount of buildings representative of the typology (single family houses, block of flats, office buildings) with different insulation levels and in different climatic conditions. The paper shows also the analysis for generalizing the results for different climatic conditions. The database will be used by non expert users, who want to know the size of the GSHP. Also expert technicians may use the database in case they are interesting in a first rough sizing of the GSHP in a very brief way. The data base will be used in the calculation tool for sizing the GSHP which will be developed in the second step of the H2020 project.

ABSTRACT. Buildings are responsible for more than 40% of energy consumption in the world. The simulation of combined heat, air and moisture (HAM) and in this context is important to predict the indoor air quality and thermal comfort. Moreover, inappropriate levels of indoor humidity and temperature can contribute to a high movement of water vapor through the building walls, causing deterioration and reduction of the thermal insulation which leads to higher energy demand. The simulation of the buildings behaviour can help to optimize the design of new or existing building, help better control the HVAC system and therefore results in energy efficient buildings.

In this work, an in-house modular object-oriented tool (NEST) for the multiphysics simulation of buildings is presented. The whole building is modelled as a collection of basic elements (e.g., walls, rooms, openings, occupancy, HVAC system, solar radiation distributor, etc.). These elements can be modelled using different physical models and scales. A combined heat, air and moisture transfer model for the building envelopes and rooms have been implemented and validated with different benchmark cases. The in-house simulation tool has been used for the simulation of hygrothermal behaviour of rooms inside different buildings (residential apartments, hospital rooms, university and school plants). The simulations will allow as the analysis of the humidity effect on thermal comfort and energy performance of the rooms.

ABSTRACT. Due to the rapid development in technology, intelligent buildings like other fields are rapidly developing. Evaluating a building intelligence will help in configuring the status of the building to show the functionality level of the intelligent components installed as well as the integration level between the different systems in that same environment where the higher integration between the systems indicates the higher level of intelligence and functionality. This research is investigating the intelligence level of a selected sustainable case study building. The similarities and differences between intelligent and sustainable buildings are compared through a case study, and recommendations are made for enhancing the intelligence level of the same building based on the criteria developed by other researchers in 2007. In the study, a 3-storey office building of Dubai Electricity and Water Authority was chosen and evaluated, which is located in Al Quoz industrial area of Dubai. Creating a working environment for 1000 employees, the most important feature of the building is its sustainability aspect. The case study is a USGBC LEED Platinum certified building with 98 points out of 110 rating from the criteria set for this green building standard. The building is considered to be the largest and first governmental green building achieving this rating in the world. The aim of this study is to provide an exemplar-building model in the UAE and the wider region setting a new standard in terms of ‘sustainable intelligent buildings’ for researchers, designers, and investors to look at and get inspired from for developing smart future building projects.

ABSTRACT. ABSTRACT In laboratory tests on standard heat exchangers, novel anti-ice coatings have shown great potential to save energy. In winter, heat exchangers for heat recovery ventilation (HRV) and heat pumps accumulate ice and require periodic defrosting. The applied organic-inorganic hybrid coatings increased the up-time between two energy-consuming defrosting cycles by a factor of 2.3. Freezing (ice nucleation) is not inhibited, but the spreading of frost, which originates from ice-nucleation sites, was inhibited. Herein, we outline the work principle and provide quantitative results.

INTRODUCTION The present work originated from freezing problems of heat recovery ventilation (HRV). At outside temperatures below typically about -3°C, the plates of the typically applied air-to-air counter-flow heat exchangers are cooled below 0°C and frost may form and grow on the side of the more humid exhaust air coming from the building. Gradually, the flow is blocked and periodic defrosting by heating is required, consuming energy. Even if frost is not completely avoided, longer up-time between defrosting cycles would significantly save energy. Similar frost problems occur for heat pumps and refrigeration.

METHODS A standard aluminium surface was compared with a hydrophobic coating. The coating is an inorganic-organic hybrid coating similar to a previously published coating [patent WO 2012/083970] providing a 2-5 µm thick film with a smooth, hydrophobic surface with advancing/receding water contact angles of about 104°/95°.

RESULTS and DISCUSSION ‘Anti-ice’ is an umbrella term for different effects such as reduced ice adhesion or freeze-delay. Freezing (=ice nucleation) occurs randomly and with a distinct probability related to temperature and surface area.

While for technical heat exchangers usually no significant freeze delay is not considered, our investigations with test plates at temperatures of 4 to 7°C revealed a comparably low ice nucleation probability, in the same range for both bare Al and the hydrophobic coating. Wet, 100 cm2 large surfaces stayed in some test runs ice-free for several hours. If ice-nucleation (freezing) finally occurs on bare Al, the whole Al surface, which is covered by a continuous water film, freezes at once. On the hydrophobic coating, condensed water forms single drops. If one drop freezes, neighbouring drops initially stay liquid. A frost spreading rate of about 2 µm/s was measured for a -4°C cold, hydrophobic surface.

We carried out a test simulating HRV, monitored according to EN 308. The exhaust air coming from the building left the heat exchanger at about -5°C. This is the area where ice usually forms. All parameters (in-/outgoing air temperature, flow, humidity) were identical for the coated and the uncoated heat exchanger. Frost was monitored by measuring the pressure drop. While frost forms inside, between the fins, for the uncoated heat exchanger, the coated heat exchanger drained more liquid water, icicles formed at the outlet. To reach an identical pressure drop, the coated heat exchanger could run 2.3 times longer.

ABSTRACT. The energy use-related effects of ultraviolet germicidal irradiation (UVGI) to mitigate biological fouling (biofouling) of a chilled water cooling coil are investigated via a field study. A visibly bio-fouled cooling coil in an air-handling unit serving an operational building in a hot, humid climate is monitored for 5 months to establish a fouled coil baseline. Parameters monitored include air flow rate, airside pressure drop, air temperature and humidity upstream and downstream of the coil, chilled water flow rate, entering and leaving chilled water temperature, and waterside pressure drop. A UVGI coil irradiation system is installed on the downstream side of the coil following typical manufacturer guidelines, and the system is then passively monitored over a period of 14 months. The change in operation is estimated by comparing data from the baseline and post-irradiation periods. The 95% confidence intervals for average improvement of coil airside pressure drop and heat transfer coefficient are 11.07% to 11.13%, and 14.5% to 14.6%, respectively. Complexities of the physical phenomena involved, in particular, the combined effect of airflow and latent load on airside pressure drop, are taken into account.

ABSTRACT. Room air-conditioners are equipped with a heat pump as the heat source and can efficiently cool and heat a room using outdoor air. Recently, the coefficient of performance (COP) of air conditioners described in catalogues has markedly increased as a result of technological development. However, the COP of air conditioners greatly depends on the operating conditions and its actual values may largely deviate from the catalogue values. Therefore, the amount of energy saved by changing the type and improving the use of air conditioners cannot be accurately estimated from the catalogue values alone. To address this problem, we simulated the heat source characteristics of room air conditioners and proposed a heat source characteristic model for estimating the COP and power consumption of home air conditioners under arbitrary operating conditions. This model has the following two features. 1) The COP and power consumption of the heat source under arbitrary indoor and outdoor temperature and humidity and under arbitrary indoor heat load conditions can be calculated. 2) These values can be calculated for various types of home air conditioners: that is, the heat source characteristics of target air conditioners can be modeled using data published in catalogues and technical specifications. In a previous study, we modeled the heat source characteristics of a highly functional air conditioner during cooling and compared the calculated values with the measured values to examine the estimation accuracy of the model. In this study, the model constructed in the previous study was applied to both cooling and heating operations to experimentally examine the estimation accuracy of the model with the aim of improving the practicality of the developed model. In Section 1, the previous model was extended to construct a new model that can be applied to both cooling and heating operations. In Section 2, cooling and heating experiments were performed using highly functional and ordinary air conditioners to examine the estimation accuracy of the new model.

ABSTRACT. Introduction In applications where dehumidification is important, desiccant systems are a good alternative to conventional air conditioners because they open new possibilities, such as the use of low temperature heat sources or control of humidity and temperature separately in an efficient way. In the combination of liquid desiccant systems with conventional vapor compression chillers, called hybrid liquid desiccant systems, the liquid desiccant unit handles the latent load, and the vapor compression system the sensible one. Despite liquid desiccant systems have many advantages compared to solid desiccant systems, such as lower regeneration temperature, chemical storage or pollutants removing, they are not often used because of the corrosiveness and carry-over of the liquid desiccant. Methodology The performance of a hybrid liquid desiccant prototype with non-adiabatic air-solution contactors is analyzed in this paper. In order to avoid corrosion all the components that are in direct contact with the liquid desiccant, which is LiCl-H2O, are made of plastic, especially the air-solution contactors that are made of polypropylene. Moreover a plasma treatment has been performed on the surface of the horizontal tubes in order to enhance its wettability when it is in contact with the liquid desiccant. The hybrid liquid desiccant system is an air-conditioner which controls separately the humidity and temperature of two locker rooms of a swimming-pool in Taipei (Taiwan). Results and discussion The experimental prototype is firstly presented. In addition, the performance experimental data of the hybrid liquid desiccant system during its operation in Taipei are shown and discussed. Thermal capacity of the system as well as the supplied air condition reached by the system are included at different ambient an internal loads conditions. Conclusions The presented hybrid liquid desiccant system shows an adequate control of the humidity and temperature of the locker rooms at different operational conditions. At the same time, corrosion which is one of the main problems in liquid desiccant systems has been eliminated because of the use of plastic materials.

ABSTRACT. Liquid desiccant air conditioning (LDAC) systems have gained increasing attention due to the improved energy performance and reduced environmental impacts. This paper presents an LDAC system using electrodialysis (ED) as well as low grade heat generated from a hybrid photovoltaic thermal and evacuated tube (PVT-ET) collector for liquid desiccant regeneration. As ED regenerator is a key component in the proposed system, a modified mathematical model is used to simulate the mass transfer of the ED stack. The performance of the model was validated using the experimental data generated based on a lab-scale experimental setup. It is shown that the model predicted concentration of the solution in the regenerated tank matched well with the experimental data. Compared to the LDAC systems using conventional thermal regeneration, the proposed ED system can regenerate the LiCl liquid desiccant solution at a low temperature. The regeneration process can also be operated during night-time. The whole system simulation using TRNSYS showed that the outlet concentration of the spent solution in the thermal regenerator was in the range of 26.87-26.97% (wt/wt). The concentration of the regenerated solution at the ED outlet can be maintained at 29.99% (wt/wt).

ABSTRACT. A new kind of air conditioning system called the chilled water wall was developed: A surface-cooling system that uses a chilled film of water flowing down on a vertical or sloped surface. In cooling/dehumidification mode, the system runs with surface temperatures well below the dew point of the indoor air. This results in combined cooling and dehumidification of the air in contact with the chilled water. The system can also be used as an air-humidifier in an alternative operation mode. In order to use the water wall in practice, its cooling and dehumidification respectively humidification capacity was determined by following two approaches: First, measurements of the specific cooling, dehumidification and humidification performance of a prototype under defined climatic conditions were carried out. The performance test is based on the protocol for testing and rating chilled ceilings. Second, a theoretical calculation model was developed, that considers the relevant heat and moisture fluxes to and from the surface of a water wall. It was successfully validated by measurements and coupled with the hygrothermal building simulation software WUFI® Plus. This allows a dynamic simulation of the water wall’s hygrothermal interaction with a room’s indoor climate and its assemblies. With the dynamic model, a simulation study was executed to investigate the impact of the water wall on the indoor climate of an office building with varying room layouts and occupancy profiles. The cooling effects were examined for single and team offices. The simulations were used to determine the necessary surface area of the chilled water film.

ABSTRACT. Passive cooling covers the natural processes of heat dissipation and heat gain operations and provides high efficient, comfortable environment around. As commonly known, when the air heated it rises, when cooled it descends. Natural cooling and heating use this physical property of air to provide the best thermal conditions.

In this study, an air to air heat pump system used for both floor heating and chilled ceiling operations was analyzed numerically and experimentally. Main objective of this study is to obtain COP of the heat pump system from refrigerant, hydronic and air sides. In order to calculate the air side capacity, counter loads installed into the room and the system was observed whether it provides comfort conditions. The test room was constructed of 100 mm PU panels to minimize the heat loss. All the data obtained from the system is recorded on a time period of per-second based during the processes. On the other hand, CFD analysis was performed with respect to the desired conditions on ANSYS Fluent 15. Air velocity, humidity and temperature distributions are analyzed inside the room.

ABSTRACT. The design of sustainable and energy efficient buildings needs alternatives for compressor based cooling and dehumidification of supply air below the dew point. The cooling demand of buildings is constantly increasing due to higher internal loads and architecual design aspects while current cooling technologies have a high primary energy consumption as well as a high global warming potential (GWP) when HFC refrigerants are applied. One alternative method of cooling and dehumidification consists of a strict separation of both processes. In a first step outdoor air will be dehumidified by a sortion process running in an open cycle while the warmed, but dry air is then cooled down by means of indirect adiabatic evaporatie cooling. Both processes only need a small portion of the necessary energy to cool down air below the dew point and heating up again to supply air temperature level as done today. This paper introduces a new concept and the technical challenges adressed in the fundamental research project “OptiMat” funded by the German Federal Ministry of Education and Research and explains the methodology of Thermal Driven Cooling.

Warm and humid ambient air passes a heat exchanger with coating of sorption material. While passing, water vapor will be bound to the coating and the generated latent heat of vaporisation is transferred to the fluid within the heat exchanger. The air will then pass a second heat exchanger where indirect adiabatic evaporative cooling cools down the supply air to temperatures below 20 °C. The water stored in the sorption material is released during a switch over process where a second ambient air flow carries the humidity released from the heat exchanger, which is then heated up by a fluid with a temperature level of approx. 65 °C. This temperature level originates e.g. from a combined power plant and uses waste heat to dry the sorption coating. The key factor for this technology is in the thermophysical properties of the sorption material. Here, the dynamic characteristics of water adsorption and desorption at a given temperature range as well as the coating process to a heat exchanger surface are of importance. Further, the material as well as any additional substrates need to be 100 % inert to metabolism processes. Sorption materials will be tested as samples as well as part of an experimental model under real operating conditions. Additionally, simulations will give a clear direction for optimisation potencials.

In a first step promissing sorption materials are identified and already tested for metabolism. In parallel the dynamic adsorption and desortion processes are characterised to be implemented into a numerical model. First samples of the materials have been tested for long term stability.

Today, several alternatives to compressor based cooling are under investigation and will result in a multitude of new technologies. The upcoming years will prove which of them are the most promissing for a sustainable building design.

We believe that sortion based dehumidification and adiabatic evaporative cooling have a high potential to substitute refrigeration systems with high primary energy consumption.

ABSTRACT. To improve the performance of the liquid desiccant system, a novel method is proposed by adding microcapsulated phase change materials (MicroPCMs) in the desiccant solution, which is expected to restrain the temperature rise in the moisture-removal process, and then the auto internally-cooled dehumidification will be achieved. The MicroPCMs to be used in auto internally-cooled dehumidification, with melamine-formaldehyde polymer as shell and liquid solid mixture paraffin as core, was prepared by in-situ polymerization method in this paper. The effects of the types and contents of emulsifier on the diameter, morphology and phase change performance of the MicroPCMs were studied by using electron scanning microscopy (SEM) ,laser particle size analyzer and differential scanning calorimeter (DSC). The results showed that, when the compound emulsifier mixture of Span80 and Tween80 in proportion of 1:1 is used, and the content of the emulsifier is 60 % of the core material, the micro-shape of the prepared microcapsule with stirring rates of 1000 r/min in the synthesis process is the sphere with smooth surface and compact microstructure. Moreover, the sizes of the microcapsules are uniform, and the average diameter of the microcapsules is 0.45 μm, the phase change enthalpy is 51.41 J/g.

ABSTRACT. Thermally Active Building Systems (TABS) have proven to be an energy-efficient and economical cooling and heating solution for commercial buildings. By using the building structure as thermal storage, this technology allows providing uniform thermal environment indoors while making possible the use of renewable energy sources. In TABS buildings however, acoustics can be jeopardized. Indeed, this solution requires large uncovered hard surfaces indoors – typically concrete floor and ceiling, which will reflect the sounds instead of absorbing them, acting as a sound mirror. If traditional fitting surfaces such as wall-to-wall suspended ceilings are inappropriate in this situation, soffit-hanging sound absorbers embody a promising solution to guarantee a comfortable acoustic environment.

The aim is to understand to which extent this layer of discrete panels will impede the performances of TABS, and how this translates on the indoor thermal comfort for the occupants. In order to address these issues, this study focuses on validation of a new TRNSYS component (Type Ecophon Acoustic Elements) which was developed to simulate partially covered suspended ceilings, such as hanging sound absorbers. Their coverage can vary, and no tool was available until now to simulate such a suspended ceiling solution in TRNSYS, to the authors’ knowledge.

In this paper, the Type Ecophon Acoustic Elements is validated by numerically modelling a set of similar experiments carried out in full-scale by a previous study. For this, a total of 12 scenarios from two case studies have been modelled, with varying suspended ceiling coverage ratios, type of suspended ceilings, internal heat gains and TABS water supply temperatures. The tests were performed in a test room with a floor area of 21.6 m2, arranged similar to an office room, equipped with floor and ceiling TABS, and surrounded by a thermal guard to ensure stable thermal conditions. The results obtained from the simulations were very close to the experimental results, both in terms of the thermal conditions in the room and of cooling performance expected from the TABS. The first set of measurements analyzed the effect of the above-mentioned parameters in the heat flow from TABS in seven different scenarios; the difference between the numerical results and measurements is in the range of -6.9% to +5.2%. The second set of experiments evaluates the impact on TABS cooling capacity coefficient and room temperatures. The simulated cases led to absolute differences +4.3% higher in average for the cooling capacity coefficient. The operative temperature in the room is particularly well estimated, with a maximum relative difference of +0.3°C over the five scenarios. This validation will allow further studies to be performed using the new numerical tool to estimate the impact of sound absorbers on thermal comfort when used in buildings equipped with TABS.

ABSTRACT. There has recently been a considerable increase in the use of concrete-core activation, or Thermally Active Building Systems (TABS), in Europe as an energy-efficient and economical cooling and heating solution for commercial buildings. This concept relies on using the building structure as thermal storage, allowing the use of renewable energy sources and providing uniform thermal environment. However, this widespread solution also features the disadvantage of requiring large uncovered hard surfaces indoors – typically concrete floor and ceiling. The surfaces of bare exposed concrete reflect the sounds instead of absorbing them, acting as a sound mirror. This can lead to a degradation of the room acoustic comfort. Therefore, challenges arise when this thermal system has to be combined with acoustic requirements. Traditional fitting surfaces, such as wall-to-wall suspended ceiling, are inappropriate in this situation. A promising solution is embodied by soffit-hanging sound absorbers.

This study focuses on quantifying the impact of such sound absorbers on the TABS performances, assessed by the cooling capacity coefficient of the ceiling deck. The influence of different ceiling coverage ratios (0, 30, 45, 60 and 80%) was studied by means of TRNSYS simulations, as well as the influence of the distance between absorbers and soffit. For this, a new TRNSYS Type (Ecophon Acoustic Elements) has been developed to simulate partially covering suspended ceilings and their impact on occupant thermal comfort when used in buildings with TABS. This tool has been validated in another study to ensure a reliable output. The tests were performed in a test room with a floor area of 21.6 m2, arranged similar to a two-person office room, equipped with floor and ceiling TABS, and with adiabatic vertical walls.

The results show that with a ceiling coverage ratio of 60% and with sound absorbers hanging at 300 mm from the ceiling, the cooling capacity coefficient of the active deck was reduced by 15.8%. The cooling capacity coefficient is further reduced down to 25.4% when 80% of the ceiling is covered. The presence of acoustic panels also affects the thermal comfort in the room: the operative temperature increased by 0.9°C in the former case and up to 1.6°C in the latter. The results also show that comfort ventilation provided to the room has a considerable effect on shaving the peaks in temperature increase, indeed causing an operative temperature increase twice as big when removed. Based on these results, it appears possible to achieve thermal and acoustic comfort with TABS. This new validated tool also enables to properly quantify the effects of acoustic panels on thermal environment and cooling performances of TABS.

ABSTRACT. OBJECTIVES: The objective of this dissertation was to analyse what the possible benefits and risks could be when adding Concrete Core Activation (CCA) to classical air-conditioned buildings in a ‘hot and humid’ climate. The characteristics of hot humid zones are completely different to those of temperate climates where many years of trail and error with different air based or radiant HVAC systems have led to near optimal operation. METHODS: The presented work is a simulation study comparing classical HVAC concepts to CCA assisted concepts in a reference building. The studied building is located in Singapore. With its low latitude of 1°17’N causing high solar radiation and the proximity of large natural water surfaces, Singapore has a climate with high humidity levels and hot daily mean temperatures. The monotonous climate without pronounced seasons can be classified as ‘Tropical’ or Aw according to Köppen’s climate classification. RESULTS The use of CCA changes the complete performance of the system and the energy consumption of the building in a positive way. When CCA is added energy consumption, operating costs, ACRs and degree-days are reduced. Even improved AC models can’t reach the same results as a worsened A+C model. When changing parameters the models with and without CCA reacted in a different way. The changes in the performance of A+C models were much less pronounced than the reaction of AC models. The possibility to improve or worsen a model is much greater for AC models than for A+C models. DISCUSSION It is also exposed that the results obtained in this study should be taken with care. Simplifications have been made so a working model can be created that can be used in simulations, while also some generalizations have been made in order to be able to consider the models as a general study object in stead of a model that only works with specific technical properties of existing components.

ABSTRACT. Introduction: In a context where buildings are more and more insulated, the energy gains through windows have an increasing impact on the energy balance of a room. The solar energy enters the building through the glazing and is intercepted by the surfaces of the floor and walls. Depending on the characteristics of the surface and materials, the energy can be more or less absorbed into the walls/floor, and released later on. The quantity of energy stored and the delay with which it is released depend strongly on the thermal mass and conductivity of the materials, as well as of the absorptivity of the surface. Concrete is known to have a very good inertia, as it combines a high thermal mass and conductivity. However concrete is mostly covered with flooring materials or coatings. This paper presents an experimental study carried out in order to evaluate how much energy could store a concrete slab, how long, and what was the impact of the thickness of the slab. Different flooring materials were also compared. Methods: Concrete slab samples were cast, with temperature sensors inside at several depths, and a heat fluxmeter was placed near the surface. 4 samples were 16cm thick, one left uncovered, the others being covered with tiling, linoleum and parquet. One sample was 4cm thick, left uncovered. The samples were exposed to an artificial solar irradiation and then exposed to solar radiation incoming through windows in a test house. Results: Depending on the colour of the flooring, the slab can absorb up to a half of the incoming radiation. With the 16cm thickness, 1/4th of the stored energy is then released in the rest of the day, 1/5th is released the day after in the absence of sun exposure, and a remaining 5% is released on the 2nd day. Those results are true for no cover or tiling or linoleum cover. With parquet the quantities of energy have to be divided by 2. If the slab is only 4cm thick, the energy store is completely released during the 1st day. Conclusion: Results show that the thick slabs can absorb solar energy during a sunny day and release it during the 2 following days and nights in the absence of sun. A thinner slab can release energy during the following night but not longer. While tiling and linoleum doesn’t affect much the storage potential of the concrete slab, parquet reduces nearly by 2 the energy stored and released by the slab. This study shows that an appropriate choice of the covering material is important to use correctly the storage potential of concrete. An important thickness helps storing energy for longer periods and can smooth energy demand on non-sunny days.

ABSTRACT. Concrete Core Activation (CCA) and Chilled Ceilings (CC) are two of the leading technical concepts in sustainable office buildings. Both water-based systems rely on a radiant cooling or heating capacity, but where CC consists of water tubes on a thin aluminium sheet and is directly controlled by the indoor temperature, CCA will create a thermally activated building system (TABS) by embedding these tubes in the concrete structure of which the thermal inertia makes it challenging to determine a good control strategy. The comparative study, using a real contemporary office building, researches and discusses the objective advantages and disadvantages of these two emission systems and their accompanying thermal supply. The search for an objective method to make this comparison is one of the main topics in this paper. Four HVAC configurations were distinguished; in this way it is possible to have a broad scope over different set up configurations. On the one hand we have CCA and a ground-coupled heat pump (GCHP) with either convectors or VAV, while on the other hand we chose CC combined with either a GCHP or a condensing boiler as representatives for real situations. The study is performed on the basis of an acoustic comparative analysis and an investigation with regard to energy use, energy balance of the soil and comfort of the indoor environment with the help of dynamic simulations in TRNSYS. In addition, an economic analysis is carried out, where the Return On Investment (ROI) is investigated, based on real investment costs, maintenance costs and energy costs but also on productivity and the influence of comfort on this productivity parameter. In this way the performance of each configuration can be assessed on both energy efficiency and comfort in the building. Regarding acoustic performance the results show that an appropriate design makes it possible to achieve high speech intelligibility for both emission concepts. However, it is harder to achieve this level of quality in buildings equipped with CCA since CC is not limited by the decrease of the cooling or heating capacity in case a more absorbent material is used. A water supply temperature closer to room temperature and the thermal inertia of CCA uses less energy, while the lack of a fast reacting cooling system causes overheating in warmer periods. CC installations will use considerably more energy with a limited shift in thermal comfort. Since CCA will be more successful in supressing the energy cost but also first investment and the total actual cost, it results in a shorter ROI period. However, when the assumption is made that an increase in comfort causes a certain productivity gain, the buildings with a higher comfort are paid back in a shorter period. It is possible to achieve an energy balance in the soil, but in warmer or colder periods we see that this balance can be disrupted, and thus accompanying these systems with a hybrid system is the only way to maintain a proper energy balance. One could conclude both systems have the ability to provide a good comfort and thus a proper hydraulic concept, but where CC will excel in a higher overall comfort, CCA will achieve a lower energy use and shorter ROI.

ABSTRACT. As a great energy and peak power savings potential system, radiant floor cooling system in the commercial building can additionally improve indoor thermal comfort. This study conducted a field study on the performance of the intermittently operated radiant floor heating system in a cold area. The results show that almost stable indoor air temperature with an approximately value of 18°C is monitored in an office room without larger internal heat source. Except that the northern window that has the relatively lower temperature about 13°C and floor that has the relatively higher temperature about 20°C, the temperature for the interior wall surfaces ranges from 16°C to 18°C. The vertical temperature difference is not remarkable with maximum difference about 0.6°C. The supply water temperature keep stable at 27°C which is sufficient to satisfy the indoor thermal environment when the outdoor air temperature ranges 0 to 10°C. The energy consumption of radiant floor heating system is summarized from Dec 21, 2015 to Jan 20, 2016, showing the heat pump consumed more than three-quarters of total energy consumption. However, due to the peak and valley power cost difference, the heat pump only operates during the time period of valley power and can benefit from this policy.

ABSTRACT. Further reduction of primary energy in heating and cooling of buildings requires new intelligent solutions in air conditioning with a high operational flexibility. One option is the functional combination of technical textiles with heating and cooling into thermo-active textiles. It is expected, that these textile constructions have a set of advantages compared to conventional panel heating and cooling systems. By way of example the outstanding applicability in refurbishment of old buildings, very flexible arrangements in the room, advantageous control, boosting, heating up and cooling by “folding” and “unfolding” should be mentioned. Small water pipes with an inner diameter of 3 mm are sewn into the textile. It is important to keep the pressure loss as low as possible. Hence, underserved areas can be avoided. Several textile prototypes with thermo-active abilities were produced. The prototypes vary in their size and water flow pattern. The dimensions are 50 cm x 50 cm and 12 cm x 120 cm. In three cases the water supply is from top to bottom and meandering in three other cases. The prototypes were analyzed for their mechanical and thermal properties. Heating and cooling performance data of the textiles have been derived from experiments carried out under reproducible conditions in a test chamber designed for this kind of testing. The test chamber is 0.84 m long, 0.51 m wide and 1.50 m high. One wall of the test chamber is a thermo-active wall, which can be controlled accurately in a temperature range between 8°C and 50 °C. All other walls of the test chamber are made from styrofoam. Additionally, comprehensive numerical studies of the thermal behavior of the prototypes were performed. First, comparative simulations of the experiments were done. Secondly, the results were transferred to applications in real rooms. The available data show a very good match between experimental and numerical results as well as a great potential of thermo-active textiles for space heating and cooling.

ABSTRACT. INTRODUCTION Concrete Core Activation (CCA) – also called Thermally Activated Building Systems or TABS – have a renewed interest in the quest towards low-energy buildings, because their low heating and high cooling temperatures allow the use of low-exergy heat and cold production systems. However, CCA is characterized by a large thermal capacity which hampers energy efficient control of the system if conventional room temperature based control strategies are used. Model based predictive control strategies can overcome this problem provided that the controller has an adequate model of the CCA floor thermal behavior. On the other hand, computation time reduction in the applied optimization routines compels simplified models. In this paper a 1D controller model for an inhomogeneous CCA floor with air cavities is constructed using measurements and a 3D finite element (FE) model to generate training and validation data.

METHODS An available 1D Resistance-Capacitance (RC) thermal model for a homogeneous CCA floor slab is adapted to describe the temperatures and heat fluxes in the investigated inhomogeneous configuration for 2 water tube positions. Initial model parameters are derived from the physical properties of the CCA floor slab. Using a grey-box methodology, a three step approach is adopted to identify the correct 1D controller model parameters. In a first step, experimental temperature and heat flow data are generated from a full-scale test setup in a controlled environment. Secondly, these data are used to validate a detailed 3D FE model of the CCA floor slab. In a last step, the 3D FE model is used to generate multiple reponse data sets, that are used as training and validation data sets for the parameters identification of the adapted 1D controller model.

RESULTS & DISCUSSION Compared to the 3D FE model, the 1D model predicts steady state heat fluxes with a maximal error of 7.5%, while the time constants of surface heat flux, induced by a step in water supply temperature, are predicted with a maximal error of 6%. The adapted 1D grey-box model is a simplified mathematical representation of the real physical processes and as such guarantees robustness against small dimensional variations.

CONCLUSION A 1D model for a CCA floor with air cavities has been successfully identified from a 3D finite element model. This model is suitable to be used for optimal control problems implemented in model based controllers.

ABSTRACT. Thermo-Active Building Systems (TABS) represent a promising option for building conditioning, being well-spread in Northern and Central regions of Europe for dominant heating operation, but having a much slower penetration in warmer Southern climatic areas. In this context, the present work aims to evaluate the potential and main implications of such climatic differences on the energy and comfort performance of TABS. Their integrated operation with different cold water generation alternatives and control strategies is considered.

After the definition of a virtual typical office building, the TRNSYS 17 software is used to simulate the performance of each case study during the most demanding cooling period (4392 hours from April to September). Also, a reasoned cost function is applied to each case in order to select the optimum operational conditions (e.g. the optimum supply water temperature setpoints) in terms of energy consumption and thermal comfort provided.

Results derived from the whole simulation work, which comprises more than 500 simulation runs in all, are divided into two different studies. Both of them consider three different climatic locations in Central and Southern Europe, as well as the comfort evaluations derived from the Fanger’s model and the EN15251 adaptive model. Study_1 compares the different cold water generation options for continuous and night operation of TABS, while Study_2 analyses the behaviour of these control strategies and a feedback control in combination with the ‘cooling tower + WC chiller’ generation case. Energy consumption, cumulated periods exceeding the thermal comfort zone and the relative humidity limits, as well as the optimum operational parameters found after the optimization methodology are provided in this paper.

Such results reveal important limitations for TABS cooling associated to humidity control issues in the hottest and most humid Mediterranean areas (e.g. Valencia). Nevertheless, other southern locations in the continental climate with quite hot and dry summer conditions (e.g. Madrid) show satisfactory results.

Moreover, this work estimates the potential of integrating hydraulic free-cooling provided by a cooling tower, and proves the interest of simple regulation strategies for TABS operation; such as the feedback control of the system’s surface temperature or the alternation of night-active and day-passive periods.

Finally, the consideration of an adaptive thermal comfort model also demonstrates the opening of many more possibilities for TABS than those associated to situations in which Fanger’s comfort criteria are assumed. This generates an interesting debate on the suitability of adaptive models for TABS buildings operated in passive regimes and its implications on a more energy-efficient exploitation of such systems in warmer climates of Southern Europe.

ABSTRACT. Heat waves are reported to be more frequent in recent years. The urban heat island (UHI) is severely exacerbated during the UHI, leading to an increase in mean/peak energy demand and an escalation in the heat-related mortality and disease. Beside the taken long-term actions by cities to mitigate UHI such as urban greening plans, the implementation of short-term mitigation strategies can reduce the immediate heat-related risks of the UHI. Predictive tools can help urban planners and decision makers in minimizing the mentioned risks. However, these tools are mainly developed based on stationary parameters of a city such as the average surface temperature, which cannot present the variation of land-use/land-cover (LULC) in various urban neighborhoods. In this study, an artificial neural network (ANN) is developed to predict the indoor air temperature of buildings in different LULCs. A four-month measurement campaign of more than 50 buildings located on the island of Montreal was conducted to obtain indoor temperatures. The island of Montreal is then separated into 11 regions where the ANN model is trained to be sensitive to three types of neighborhoods, including high-rise, residential and industrial. Hence, the effective radius on buildings’ indoor temperature is found for each region to be within a radial area, where the environment beyond its limit does not significantly impact the building indoor air temperature. The effective radius was observed to lie within 320m to 380m.

ABSTRACT. In recent years increased attention is being paid to the urban microclimate and its consequences for the thermal performance of buildings. This paper provides a microclimatic analysis of a sample of different courtyards in Vienna, Austria. The goal of this research is to analyze the thermal behavior of geometrically different courtyards and compare them to adjacent street canyons in terms of temperature, humidity, wind speed, and CO2. The courtyard typology was considered due to its standing as a prominent architectural element in many European cities and its potential role in formulating adequate mitigation measures pertaining to heat stress in urban areas. Previous studies have shown that the orientation as well as the height of buildings surrounding courtyards has a decisive effect on the microclimate inside the courtyard. The data acquisition was subdivided into two different phases. For the first phase (April to July 2015), measurements were conducted using two mobile weather stations at 10 different locations in Vienna, Austria. At each location, conditions were captured during afternoon hours both inside and outside the courtyard. Additionally, in 3 of these locations morning and nighttime measurements were conducted. In the second data acquisition phase, temperature sensors were installed in 4 different courtyards in order to record full diurnal cycles. All locations are located within the inner districts of Vienna and include courtyards that vary significantly in size, height-to-width ratio, and amount of vegetation. Using the collected data, site-specific microclimatic conditions inside selected courtyards were systematically studied. Results show the importance of the height-to-width ratio in view of the courtyards' microclimate, as it appears to be consequential for the day-night temperature differences. The specific geometry of a courtyard and the corresponding shading extent of building walls influences the potential for night-time cooling within the courtyard. When compared to the adjacent street, geometrically open courtyards show slightly more favorable thermal conditions, especially during morning and evening hours. Only during the early afternoon hours, when the sun is at its highest position, such courtyards remain warmer than the adjacent street canyon. In contrast, courtyards with high height-to-width ratios remain warmer than the street during morning and evening hours. We also compared humidity, wind speed, and CO2 concentrations in courtyards and adjacent streets. The results point towards slightly more favorable conditions inside courtyards.

ABSTRACT. Background: Predicting near future building performance is an important aspect of demand response, which was highlighted in the Horizon 2020 societal challenges work programme by the European Commission. Past research (reference will be listed in full paper, same below) shows that the optimisation of energy management with weather forecasting can generate 15-30% savings in most cases. Therefore, it is crucial to develop a method of gathering reliable weather forecast data and applying the forecast data into building simulation or building energy management system. Since 2011, the Meteorological Office (Met Office) in the UK released 3-hourly site-specific forecast data feeds for nearly 6,000 locations in the UK through the Met Office DataPoint in a format that is suitable for application developers. This provided a great opportunity for building simulation professionals to re-use Met Office data for predicting near future building performance in the UK. Aims: With the freely available high frequency weather forecast data, the aim of this research is to create localised near future weather data for predicting the performance of buildings in the UK. Investigative approach: The project is built on authors’ previous research experience in future weather data and building performance modelling. The research approach is: (i) developing a method of collecting near future weather forecast (3-hourly for next 1-3 days) for nearly 6000 locations in the UK; (ii) applying the similar method to collect hourly weather observation data from 140 weather stations in the UK; (iii) comparing the forecast with observations to understand the accuracy of near future weather forecast in the UK; (iv) Converting the human readable weather forecast files (.xml) into building simulation software readable weather files (such as .epw format) and conduct building performance prediction. This involves data interpretation for a number of parameters such as temperature, humidity and solar radiations. Main conclusions: The authors developed a solution to re-use Met Office weather forecast data in building simulation field and building energy management system. With the large data sets available for nearly 6000 locations in the UK, it provides a potential to create ‘real weather data’ for locations that do not have weather observation station. The ‘real weather data’ not only can reduce the errors in calculation of energy demand, but also help narrow down the performance gap by providing localised weather data. The authors expect to understand the accuracy of near future weather forecast through the comparison between forecast and observation. Authors have an integrated view of weather forecasting in the UK and its impact on thermal comfort and energy efficiency of buildings. The difficulty in implementation of integrated weather forecast at building simulation is also addressed in the paper.

ABSTRACT. Climatic data are very important for determining the using of heating and cooling of buildings. At the same time they are the basic for determining the ground temperature in the different locations, as well as for determining the potential of using geothermal energy. For promoting the diffusion of GSHP (Ground Source Heat Pumps) a tool for sizing these systems will be carried out in the H2020 research project named “Cheap GSHPs”. The paper presents the set up of a consistent data base of weather conditions for the tool which will be used by both expert technicians and also non expert users. The sets of data have been collected by the TRY data base of EPW files as well as the one of Meteonorm. The different locations have been labelled in terms of DD for heating and cooling as well as by the Koeppen-Geiger scale. The work presents a classification of weather conditions in Europe, in order to help the user in selecting the weather conditions which are closets to the location of interest. The data base will be used in the selection tool which will be developed in the second step of the H2020 project.

ABSTRACT. While simulating complex systems, information exchange among components is one of the most important aspects. A specific kind of information is that related to weather data. The format of the climatic data diffusely used in Building Performance Simulation tools (BPSts) contains information about weather variables which are different from each other as far as concern their nature and timing. They have a statistical origin and, in the majority of the cases, are provided on an hourly basis. Given this inhomogeneity and hourly time base, care had been taken to manage their timing and different approaches are today’s in use by BPSts. Furthermore, when the building involves complex components and control strategies, sub-hourly simulation are needed to understand the efficiency of the enquired system. This necessity has led to the implementation of even more different interpolation routines. The capability of these interpolation routines to represent weather conditions that change much more frequently than shown on an hourly basis is here investigated. Besides, BPSts are today used also at operational time, as predictive tools for control strategies and/or Fault Detection and Diagnosis. In this scenario, the statistical validity of climatic data is not anymore sufficient, while their variability profile, recorded with high frequency, and their correct interpretation/synchronization (integral values vs instantaneous values), might became relevant. In this article will be presented a review of the choices implemented by two well-known software, such as TRNSYS 17 and EnergyPlus 8.4.0, to handle weather data and further considerations will be made upon possibilities offered or denied by this choices when different components are involved in the simulation.

ABSTRACT. Assessing natural ventilation potential on a tropical island such as Tahiti (French Polynesia), where strong climatic constraints apply on buildings, constitute a challenge due to the scarcity of wind measurements. Indeed, only one in situ automatic weather station provides high quality wind speed and direction data. To overcome this lack of information, a dynamical downscaling method using WRF-ARW model has been performed to assess 10 m wind speed and direction at high spatial resolution in Tahiti. A weather type classification is used to highlight the main regimes prior to the downscaling process. First of all, daily 700 hPa geopotential and 10 m horizontal wind components from ECMWF reanalysis undergo a clustering technique resulting into six wind classes. Then, the five closest dates to the centre of each wind class are selected. Simulations with the model WRF-ARW are then performed for selected days over 3 interactively nested domains over French Polynesia, with finest horizontal mesh size of 1.33 km over Tahiti island. The initial and coupling fields are derived from the ERA Interim ECMWF reanalysis. The only one in situ station is then used to assess the performance of the downscaling. The higher resolution wind regimes obtained with this model set-up allowed to highlight the contrast between the leeward and windward side of the island. Better resolving the complex topography of the volcanic island, these high resolution recurrent wind regimes would be useful to support low environmental impact construction policies.

ABSTRACT. Recently, a number of research efforts have been initiated towards a better understanding of the microclimatic variance in urban areas, due to factors such as urbanization, presence and density of industrial or commercial buildings, green areas, bodies of water, etc. Moreover, the habitability of cities is subject to change especially with regard to climate change. Both of these aspects may have a decisive effect on the performance of buildings. In this context, the present contribution focuses on assessing the microclimatic variations for a number of locations within the city of Vienna, Austria. The selected sites include both high density urban areas and low density suburban domains. Furthermore the impact of this location specific weather information on building performance simulation results will be evaluated. In a first step, measured weather information on four relevant weather parameters (temperature, radiation, humidity, and wind speed) in different locations was obtained for a period of four consecutive years (2010 -2013). Using the collected data, site-specific microclimatic conditions of the selected locations were systematically studied. For this purpose the variance of each weather parameter over all locations was calculated annually, over the whole period and seasonally. Secondly, a representative number of buildings was selected and made subject to systematic thermal performance simulations using the above mentioned location specific weather information as boundary conditions. The computed performance indicators were then compared and analyzed across all locations. Additionally, the results were also compared to performance indicators derived from simulations based on the standardized weather data commonly used for Vienna. The results of this study point towards a considerable variance in urban microclimate in Vienna. Significant differences in the four relevant weather parameters were observed. It was thus established that urban microclimate displays a notable variance across a city. Moreover, this variance has important ramifications for the simulation-based assessment of the energy performance of buildings. An additional comparison of these results with the results of a simulation with standardized weather data highlights the potential for major misestimations of the thermal performance of buildings. This demonstrates the need for location specific and dependable weather data in order to properly predict a buildings thermal performance.

ABSTRACT. There is a search for sustainable design buildings with less environmental impact; the use of modern building techniques and reduce water and energy consumption becomes an increasing demand for the development of the Brazilian labor market. The civil construction industry concentrates its efforts in technology in order to seek to develop closure systems, walls, roof and the use of natural and artificial ventilation with better thermal performance. The influence of gain control and heat loss between the external and internal environment of the building is one of the main parameters of construction. Due to the daily temperature variations in the external environment and the thermal capacity of the envelope of the building, there are building materials suitable for use during the work for sealing the heat of the domestic environment, which, however, are not really considered by the building industry. Alternatively, when used the proper materials and considered the local climatic conditions, the ventilation strategy HVAC or AVAC: heating, ventilating, and air conditioning in Brazilian sustainable buildings provides a significant improvement in the thermal comfort of the building

ABSTRACT. Low temperature district heating (LTDH) can substantially reduce total greenhouse gas emissions, increase reliability of the energy systems, enable transition to the renewable energy society, and secure energy supply for future development of society. To enable successful transition to the LTDH existing buildings need to undergo certain changes. Most of the existing residential buildings have heating systems based on the high and medium temperature level. Therefore, the aim of this study was to analyse the possibilities and challenges of introducing fourth generation district heating, also known as LTDH. Based on the building statistics in Norway, an end terrace house built before 1980 with a heating system consisting of only high temperature radiators was selected as a reference dwelling for the analysis. The analysis was extended with the dwelling built as the low energy and the passive house standard. Models were developed in IDA-ICE. The analyses were performed for different heating system sizes, different energy efficiency scenarios, and different control strategies. The results showed that the reference dwelling without any oversizing of the heating system might be heated up to a set point temperature of 21 °C about 80 % of the year when using the LTDH system. If the heating system would be oversized with 30 %, this set point temperature was achieved 94 % of the year with the LTDH system. To maintain satisfying thermal comfort all the year in the reference dwelling with LTDH, the heating demand had to be decreased by 63.9 % without oversized heating system or a new control strategy should be introduced in order. The reduction of the heat demand was achieved by implementing the energy efficiency measures such as all windows were replaced and insulation to both walls and roof was added. When a heating system was 30 % oversized, the heating demand should be decreased by 51.3 % in order to attain the same results. In this case, all windows should be replaced and wall insulation should be added. If the heating system would be oversized by 100 %, the satisfying thermal comfort could be maintained all the year with the LTDH in the reference dwelling without any additional measure. New control strategies for the heating system enabling heat storing in the building thermal mass might provide desired results. If the terrace house was built with the low energy standard or as the passive house standard, the LTDH system might be implemented directly without any challenges and satisfactory thermal comfort was achieved always. If the temperatures in the district heating is reduced below 70 °C, new and efficient solutions has to be implemented in the existing substations in order to ensure safe and efficient low temperature tap water production. The most important conclusions was that the existing buildings, built before 1980, might be connected to the LTDH as long as sufficient heat was delivered. In the case when more heat was necessary, the control adjustment on the heating system should be made. In that why a transition to the LTDH can be made easily and without risk for decreasing indoor thermal comfort.

ABSTRACT. Introduction: In modern societies buildings significantly contribute to the energy demand and account in some countries for up to 50 % of primary energy consumption. Thus, scientific community and industrial sector intensified research on energy consumption and efficiency in buildings. The growing interest is a result of many factors, including integration of renewable energy sources and storage systems. Detailed knowledge on the building demand fosters decentralized energy production. On-site generation with local energy management is a feasible and inexpensive approach to improve energy efficiency and reduce costs. This paper presents a feasibility study for the installation of on-site energy generation systems in public buildings.

Methodology: Detailed demand profiles of buildings are required to determine the cost-effectiveness of on-site energy generation. A building energy assessment tool is employed to estimate the building energy consumption and supply costs. The integrated sensitivity allows studying the effect of changes in the building configuration and the profitability of on-site generation is evaluated using Net Present Values. The procedures have been implemented in the Matlab environment.

Results: The case study considers the building of a research centre in Madrid with a capacity for 150 researchers. It is shown that small changes in the building temperature and energy tariff have a considerable effect on the total energy costs. In contrast, some modifications of the building envelope (e.g. transmittance of walls and solar factor of windows) do not affect the energy balance. The building energy assessment tool was used to evaluate the effect of additional generation systems. Simulations for PV (35 kW) and CHP (110 kW) systems were carried out with and without tax on self-consumption. For both systems the tax led to an important increase in energy costs (+15.6 % and +14.8 %). Without the tax a small cost reduction (-2.3 % and -3.1 %) was achieved. The feasibility of PV installations considering the initial investments was studied. The Net Present Values showed that the installations without tax on self-consumption reach profitability for annual increases in the electricity price of 2.15 %. With the tax the PV systems are profitable for annual electricity price increases over 3.15 %.

Conclusions: A building energy assessment tool is employed to generate realistic demand profiles and to identify critical building parameters that can be used to reduce energy consumption and supply costs. The cost-effectiveness of additional on-site generation systems is determined using the concept of Net Present Values. The study provides building managers with helpful information in the decision making process. The proposed procedure is used to evaluate the installation of PV and CHP systems in a research centre in Madrid. Both systems gained small benefits without a tax on self-consumption and led to considerable economic losses when applying the tax. The results demonstrated that this tax jeopardizes any advantage of local generation. The Net Present Values showed that the feasibility of PV installations depends heavily on the evolution of the electricity prices.

ABSTRACT. The present decentralized heat production in urban areas is characterized by a wide spectrum of consistently fossil fuel based equipment. The integration of renewable energy and cogeneration technologies require increased flexibility from both sides of production and consumption. This study explores the potential primary energy savings achievable by connecting existing buildings and energy systems by means of a multi-temperature level district heating system. For this purpose, a district in Berlin with single and multiple family dwellings, a school and a commercial building has been modelled and simulated with the existing heat supply systems. Furthermore, a potential analysis for the installation of solar thermal collectors has been conducted with the focus on the temperature levels of heat production during an entire year. The results show that since the installed capacity of heat generation is often higher than the required heat demand, the systems efficiency may be enhanced by extending the supply to neighboring buildings and turning off the less efficient boilers. The results also suggest that the operating period of the cogeneration system, initially designed to cover the heating demand of non-residential building, could be extended through the whole year by providing domestic hot water to neighboring dwellings. Furthermore, the total energy efficiency of the oil/gas boilers can be increased by connecting them, which allows a more selective and prioritised operation. In summary, this paper indicates that heat sharing between buildings with different consumption profiles and different energy systems is advantageous from the energy efficiency standpoint, but requires further development of the infrastructure and control systems.

ABSTRACT. Integrated thermal energy systems provide heating and cooling for several commercial and residential buildings. These systems usually have both short-term and seasonal thermal energy storages. High cooling demands lead to a big amount of excess heat. This heat could be exported to a district heating system. Low temperature district heating can increase the integration of renewable and waste energy sources and may significantly contribute to the overall efficiency of future energy systems. In this study, the interaction of an integrated thermal energy system in Norway with district heating was investigated. The main parts of the energy system were heat pumps with 1 MW total cooling capacity, solar thermal collectors as well as water tanks and boreholes for thermal energy storage. It was assumed that heat from the solar collector tank could be exported to the district heating supply line, while the condenser heat from the heat pump was considered to be exported to the return line. Dynamic simulations were performed using a Modelica model of the energy system. An important result of the system simulations was the energy balance of the borehole thermal energy storage. Without heat export, the storage was charged more during summer than it was discharged during winter. This imbalance could lead to a ground temperature increase. To ensure feasible long-term operation of the energy system, the average annual ground temperature should remain constant. By exporting heat to the district heating system, borehole heat balance could be achieved and operating costs could be reduced.

ABSTRACT. Olive oil is an ancient food product essential to the daily life, especially in the Mediterranean region. More than six thousand years old olive oil production methods are still in use today. However, as a result of the Industrial Revolution’s influences, there are contemporary methods discovered for the mass production and these methods have increased the carbon emissions that trigger the global warming. In a typical olive oil production plant, there are two parts of the space use; the management and the production line. The management part requires thermal comfort conditions; heating, ventilation and cooling. Second part; the production line’s energy requirement based on the capacity of the process, and there is not any requirement for human thermal comfort. The proposed model will provide energy for the production line and also the heating/cooling requirements of the management part. In the considered system, the briquettes will be made from waste of the olive oil process where these briquettes will be used as an energy resource for the olive oil plant. Also, the architectural design of the plant will be planned according to the local climate conditions. The results show that the waste of the olive oil extraction is more than enough to provide necessary energy requirement of the olive oil factory. By considering the 2500 kg/h olive flow rate of the olive oil production process, 990.1 kg/h briquettes can be obtained and only 400 kg/h of these briquettes is enough to achieve the aim of zero energy olive oil production plant.

ABSTRACT. 1 INTRODUCTION The technique for using underground heat and solar heat for air-conditioning is very effective for the CO2 exhaust reduction. When solar heat and underground heat are used for cooling and heating, another heat source such as heat pump and boiler, will be often used to supply steady cold and hot water for HVAC system. However the initial cost of those equipment is not cheap. In addition, when underground heat is used, it is necessary to lay the pipes or piles under the soil, and it leads to high initial cost, which disturbs the widespread of these kind of system. Then, we proposed the system that uses the renewable energy by bringing water from the pipes and piles under the soil, and solar collectors on the roof, into the concrete floor and ceiling slab directly without any other heat sources. To lay the pipes under the soil, rolled pipes are set as they are, to reduce construction time greatly. Piles are recycled by using the pile with the shuttlecock on the head of the pile. Concerning the solar collector, we developed the simple one, which can be used even when repairing the building. The cost is verified through an actual design and construction of the building, and it aims at the establishment of the best design and the construction technique. Moreover, the performance of the system is evaluated by the measurement of the building.

2 METHODS The following verifications are chiefly executed in this study 1) Performance of the cooling and heating load reduction by using underground heat and solar heat is verified. The heat storage effect in the concrete slab, and the radiation effect from floor and ceiling for thermal environment are also verified. 2) Efficient construction technique of underground heat collecting system using pipes and piles under the ground, and also solar heat collecting system on the roof, is verified. Cost performance is also verified. 3) Compatibility with the dehumidification system e.g. normal fun-coil unit, desiccant air-conditioning unit and outdoor-air processing unit, is verified.

3 RESULTS and DISCUSSION COP (coefficient of performance) of this system is about 12.0, because this system does not have any heat sources, but also pumps which supplies the water from soil and solar collector to the concrete slab optimized by inverter. The amount of the CO2 exhaust reduction is about 4.0 kg-CO2/m2 by measurement from July 19 to August 22. It becomes about 8.1kg-CO2/m2/year. Concerning the energy reduction rate of the air-conditioning system, about 20% energy conservation is achieved.

4 CONCLUSIONS In this study, we proposed the thermal storage radiation air-conditioning system from the concrete slab that uses underground heat and solar heat directly without any other heat sources that was able to be used at a low price and for the long term. The proposed system can achieve high performance, and the practicality of it will be high.

ABSTRACT. The implementation of Power-to-Gas future technology in the building sector is new. In GEMEN, this implementation was investigated on plausibility to cover the demand of space heating and hot water in buildings. The final goals are to substitute the whole fossil methane by the use of self-produced renewable methane, the inception of saisonal storage and the dynamic convergence of the three grids power supply, methane infrastructure and district heating. The only change of this energy carrier methane, from fossil to renewable, allows to maintain the whole existing infrastructure (in Switzerland about 20 Billion Euro) including the existing end devices, such as the gas heating for instance. Knowledge about this could be important for future development of end devices over all. The goal is to fulfill exactly the aims of the energy policy of the Swiss government. The impacts in this example by substituting around 11 TWh/a of fossil methane by renewable methane are considered at contemporary dwellings. Arround 120 Mio. m2 total floor area are connected to the actual gas distribution system. In cooperation with in future affected stakeholders like power supply companies, public authority for permits, industry etc. and based on three case studies, potentials were analyzed and know-how transfer was hold exploratively. From a technical point of view it can be confirmed, that the implementation of Power-to-Gas in the building environment is feasible and also according to the guideline of the Swiss energy policy. For example by substituting the fossil methane for the renewable methane, compared to the currently emission of 2.9 Mio. CO2 t/a, a reduction of the emission between 1.0 - 2.3 Mio. t CO2/a can be achieved. The implementation of Power-to-Gas in the building environment will reform the relations between the common energy-grids. For this conversion there are still some drawbacks to be handled, which are kind of technical but especially social-economical hurdles. That regards upgrades like Power-to-Gas plants, seasonal energy storage for renewable methane and additional production of renewable electric power and new collaborations between different energy-providers. For this options till 2050 are illustratet. They shall open the discussion among the responsible groups of players.

ABSTRACT. Net Zero Energy Buildings (nZEB) imply reduced consumption by means of good insulation, passive strategies and highly efficient energy supply systems. Among other micro cogeneration systems are considered as one of the system solutions with highest potential to enable nZEB. These systems entail production of electricity and usable thermal energy (heat and/or cooling) to cover the energy demands of residential buildings, high energy efficiency levels and a locational criterion concerning the proximity of the energy source to the building. The principle of cogeneration exists for long but the interest in cogeneration technologies based on renewable energy sources has increased tremendously in the last decade. A significant amount of experimental and modelling research has been recently done in new and emerging technologies, especially in systems based on renewable energy sources (for example, solar, wind and biomass). Four main technologies are assessed: Fuel Cells (FC), Photovoltaic thermal (PV/T), solar thermal HP/ORC and cogeneration solar Thermoelectric generators.

This paper aims to give an overview of the state-of-the-art developments, discuss the fundamental and technical challenges facing commercial adoption and prospects of these technologies, particularly for single-family houses. A schematic of each technology, a table comparing the technical characteristics and a radar chart contrasting the strengths and weaknesses of each technology in market diffusion are provided.

ABSTRACT. It’s of great importance to improve the energy efficiency of the air-conditioning system and reduce its energy consumption. To improve the performance of air-conditioning system, thermodynamic analysis is supposed to be a theoretical approach. Different from a conventional method mainly through calculation or simulation, this method focuses on the internal losses existing in the system and aims to propose principles for construct an energy efficient system. To focus on the essential of indoor thermal built environment, thermal analysis according to thermodynamic parameters are emphasized. The thermal analysis method is to identify the losses occurring in the system and try to find approaches for performance optimization through reducing losses. Exergy (with a same theoretical basis of entropy) and entransy are two common thermal parameters. In the present study, similarity and distinction between exergy analysis and entransy analysis in the air-conditioning system are investigated. Both heating or cooling capacity Q and temperature level T are concerned to the energy performance of the air-conditioning system. By contrast with conventional perspective only emphasizing on Q, exergy or entransy analysis takes influences of both Q and T into account. There are different perspectives between exergy analysis and entransy analysis. Exergy is a theoretical parameter based on the second law of thermodynamics, which is suitable for characterization of heat-work transformation. While entransy is a theoretical parameter for analyzing the heat transfer process, focusing on the transfer ability. Choosing a sensible heat exchanger as an example, formulas of exergy destruction and entransy dissipation are given in the infinitesimal form. It shows there is only a difference in factors between expressions of exergy destruction and entransy dissipation. Compared with entransy dissipation, exergy destruction is related to a coefficient equaling to reference temperature TR divided by the product of fluids’ temperatures (Th•Tc). In the common temperature range of air-conditioning system, variance of this coefficient is limited. Thus analyses using exergy destruction and entransy dissipation tend to be in accordance with each other. However, result of exergy analysis is related to the reference state, while in entransy dissipation analysis on transfer process there is no concern about reference state. In coupled heat and mass transfer processes, there are also similarities in exergy destruction and entransy dissipation analyses. Reasons leading to losses could be distinguished either by exergy or entransy analysis. Then it’s helpful to improve performance of a handling process through reducing exergy destruction or entransy dissipation. In the end it’s concluded to choose different theoretical parameters based on different purposes in air-conditioning system: to improve performance of a transfer process, entransy is more appropriate; to analyze a heat-work conversion process, exergy is more recommended. The analysis introduced in this paper is beneficial to choose an appropriate theoretical tool for performance optimization of air-conditioning system.

ABSTRACT. INTRODUCTION The T-Q diagram is a widely used tool in the industry to optimize the design and the number of heat exchangers in a process. The innovation produced by the IEA EBC annex 59 project – High temperature cooling and low temperature heating in buildings – is to use this tool for HVAC systems analysis in the design phase and for the choice of indoor terminal units. The subtask A of annex 59 project develops the theoretical aspects underlying this diagram and its application for HVAC systems analysis. The principle consists in minimizing the quantity ∫Tdq in WK called entransy dissipation. It is represented by the area located below the curve which expresses the fluid temperature as a function of the power-heat transferred in a heat exchanger or in a fluid mixture within the HVAC system. This entransy dissipation quantifies the irreversibility of heat transfer. As for industry, the goal is to reduce this area, thus reducing the temperature differences between heat sources and heat sinks. METHOD We performed an experimental study in climatic chamber in order to apply the T-Q diagram method for the choice of the best indoor terminal device in an office submitted to a summer climate in Brussels and for the choice of the operating parameters water flow rate and water temperature. We tested four terminal units coupled to a water tank cooled by using a reversible air-water chiller. The four indoor terminal devices are: a mixing ventilation, a displacement ventilation, the mixing ventilation combined with a low inertia hydronic radiant floor, the displacement ventilation combined with the low inertia hydronic radiant floor. The low inertia radiant floor is basically intended for use in heating during winter season and cooling during summer season. It is very well suited for the renovation. The tests are performed under stationary conditions. We plot the T-Q diagram and we assessed the entransy dissipations for each system and various operating parameters. We measured thermal comfort within the climatic chamber and the temperature stratification. Then we assessed the COP of the chiller for the different cases. RESULTS AND DISCUSSION Air systems are less efficient than ventilation combined with radiant floor because they need lower water temperature (10.8°C and 11.6°C versus 14.5°C) without maintaining the same indoor thermal comfort level than combined systems. The combination of displacement ventilation with radiant floor is the best system because it needs the highest water temperature (14.5°C) while maintaining a high thermal comfort level. The combined systems increase the chiller COP by 6.1% compared with mixing ventilation. Entransy dissipation values represent the real quality of the indoor terminal units in terms of COP and thermal comfort level. CONCLUSION The T-Q diagram method was used for assessing the quality of the HVAC terminal unit in terms of energy efficiency and thermal comfort. It is a support tool for the decision and the choice in the design phase of the system. This early work was performed in cooling mode and the extension of this study would be to conduct experiments in heating mode.

ABSTRACT. INTRODUCTION Energy consumed by air-conditioning systems accounts for an increasing ratio of the entire energy consumption. Series of periodic heat transfer processes, such as floor with phase change materials, night ventilation, and buried pipe heat exchanger, involve in air-conditioning systems for the construction of built environment. These periodic heat transfer processes following an one day or one year cycle can be regarded as heat transfer between the heat extraction/release fluid (i.g. air and water) and an intermediary with thermal inertia (i.g. floor, building envelope, soil). The temperature difference loss between heat charge and discharge of the intermediary plays a crucial role in the energy performance of the whole system. The influencing factors affecting the temperature difference loss of the periodic heat transfer process need further investigation.

METHODS A simplified one-dimensional plate with variable Neumann boundary conditions was used to analyze the heat charge and discharge characteristic of the intermediary with thermal inertia. The periodic heat conduction processes in the intermediary was numerically simulated with finite difference method. The temperature difference loss between the heat charge and discharge processes is described by equivalent thermal resistance which is defined by Entransy dissipation. Through non-dimensional analysis on the heat conduction process, the static thermal resistance, the Fourier number, and the heat flux distribution have all been investigated in terms of the influence on the equivalent thermal resistance.

RESULTS AND DISCUSSION In this study, two kinds of heat flux distribution which are square wave and sine wave are taken as cases to illustrate the influence of the positions and duration of heat charge and discharge processes. The equivalent thermal resistance of the occasion that heat charge and discharge processes happen at the same side of the intermediary is smaller than that of the occasion that heat charge and discharge processes happen at the different sides (i.e., the upper surface and lower surface) of the intermediary under the same heat flux distribution. The ratio between the equivalent and static thermal resistance increases with Fourier number regardless of the positions of heat charge and discharge under the same heat flux distribution. Besides, the duration ratio between the heat charge and discharge process influences the equivalent thermal resistance. The greater the difference in the duration of the heat charge and discharge is, the larger the equivalent thermal resistance is.

CONCLUSIONS The temperature difference loss for the intermediary with thermal inertia during a periodic heat transfer process can be described by equivalent thermal resistance. The positions and duration of heat charge and discharge processes significantly affects the temperature difference loss. This study has important implications for the optimal design of the intermediary in a periodic heat transfer process in order to realize high temperature cooling and low temperature heating.

ABSTRACT. Nowadays in the European framework the good practices for high-performing buildings realization and retrofitting are copious, but what emerges is the lack of information and data sharing about them. There are indeed no official sources for data deriving from this kind of buildings and, moreover, there is shortage of quantitative and comparable data. In a process oriented to a large-scale diffusion of nZEBs on the market, the existing good practices of actual case studies of high-performing buildings should be kept as market benchmarks and reveal to be precious sources of information. In the light of the above, the need of a harmonized database to collect and share data deriving from different building typologies and climatic zones plays a fundamental role. Up to now various practices attempting to collect data about nZEBs can be identified; it is possible to identify two principal kinds of them related to two different levels of data collection. A first type database, which collects general information about a great number of buildings (requiring few and perfunctory information), reveals to be useful to provide statistical overviews at a large-scale. While a second type database collects data (regarding to climate conditions, building geometrical information, envelope features, systems configurations and operational parameters) of single building in a detailed way so that the energy modelling could be performed. Due to the weakness of the existing databases and to the necessity of having practical guidelines to design nZEBs, at the Italian level, an AiCARR teamwork is targeting the development of a design guide for nZEBs in Mediterranean region, based on different national experiences. In order to reach this target they have created a second type database, useful to collect and share detailed information about single high-performing buildings. Its main purpose is to record nZEBs, which have been already built, with available monitored data and that represent concrete models for future designing. Because of the still scarcity of monitored nZEBs, the database is suitable not only for realized monitored buildings but also for those that are still in a design phase. Nowadays, three different case studies are catalogued in the database. The first consists in a single family house born from the refurbishment of a traditional rural building, widely diffuse in Piedmont Region (North Italy). The second one, placed in Treviso (North Italy) is a historical edifice (a convent) transformed in a residential building. The third case study is referred to a public demonstrative non-residential NZEB. This multi-zone building will be built up in Naples (South-Italy, Mediterranean climate) and it will host office, conference and expo spaces.

ABSTRACT. In the design phase of a building, many HVAC systems options are available to satisfy the basic requirements related to its use. The design engineer is responsible for considering various systems and recommending a system that will meet the project goals and perform as desired (ASHRAE, 2008). In addition, strong regional regulations, such as the Energy Performance of Buildings Directive (EPBD) in European Union, impose high efficiency requirements to the HVAC equipments available on the market and to be installed in the buildings. As a consequence, major improvements have been made by manufacturers to improve the performance of their systems and meet all these criteria. Current technologies in the market now only have a small window of opportunity still open for improvements (Brelih & Seppänen, 2012). With the nearly zero energy goal for all newly constructed buildings in Europe after 2020, it seems very likely that the design of the future building should rely on today’s technology to meet these targets. The integration of High Temperature Cooling (HTC) in buildings can bring a fresh perspective in this context. The first part of the study presents the sensitivity analysis of a primary system to chilled water supply temperature. The system is composed of a water cooled chiller with a cooling tower and a free-chilling heat exchanger. The analysis of the system is based on semi-empirical models tuned with manufacturer data at full and part load in large range of operations. This section allows a proper assessment of the impact of the chilled water temperature on the primary system performance. In the second part of the paper, the analysis is extended to the entire system integrated in a high efficiency office building, considering distribution, emission and ventilation systems. Results are presented at first for a few hypothetical operating conditions including the summer sizing point. A full year simulation is then presented together with a sensitivity analysis of the internal heat gains impact on the total system performance. These results will allow to draw conclusions on the impact of chilled water temperature on the system performance. It will also give guidance on the sizing and the control of such system in the frame of nearly zero energy buildings.

ABSTRACT. Heat recovery device are popular utilized in the air-conditioning systems to recovery the energy from indoor exhaust air. Heat recovery efficiencies, including enthalpy recovery efficiency, sensible heat or latent heat recovery efficiency, are adopted as index to evaluate the device’s performance. However, more transportation energy will be consumed with the heat recovery device, such as fan consumption due to more pressure drop through the heat recovery device. The recovered energy of the device is cooling or heating capacity (Q), and the consumed transportation energy is electricity (W). A heat recovery COP is then defined as Q/W, which has similar definition as that of chiller. The amount of recovered energy Q will have to be removed by conventional air-conditioning system without heat recovery device. Therefore, the reference COP is calculated by Q divided by the energy consumption of the air-conditioning system. Take the summer condition as example, the energy consumption of the air-conditioning system includes the energy consumption of the chiller, cooled water pump, cooling water pump and cooling tower. The annual heat recovery COP is then compared with the annual reference COP. If the heat recovery COP is higher than the reference COP, heat recovery device is suggested in the system. Otherwise, heat recovery device will not be suggested. The comparison results rely on not only the heat recovery efficiency of the device, but also on the local climate and the performance of the reference air-conditioning system. Experimental study on the enthalpy recovery wheel is carried out, with silica gel as the solid desiccant. Heat recovery efficiencies as well as energy consumption of the fans are experimentally obtained. The building in Beijing, Shanghai and Guangzhou are investigated, the annual heat recovery COPs and the reference COP are compared. The larger the difference between indoor and outdoor parameters, the heat recovery device has more superiority. The performance of heat recovery device is best in Beijing, and the worst in Guangzhou, even with the same heat recovery device.

ABSTRACT. Floor covering resistance (material and thickness) can be influenced by subjective choices (architectural design, interior design, texture, etc.) with significant effects on the performance of a radiant heating and cooling system. To study the effects of floor covering resistance on system performance, a water-based radiant floor heating and cooling system (dry, wooden construction) was considered to be coupled to an air-to-water heat pump, and the effects of varying floor covering resistances (0.05 m^2K/W, 0.09 m^2K/W and 0.15 m^2K/W) on system performance were analyzed in terms of energy and exergy.

In order to achieve the same heating and cooling outputs, higher average water temperatures are required in the heating mode (and lower temperatures in the cooling mode) with increasing floor covering resistance. These temperature requirements decrease the heat pump’s performance (lower coefficient of performance). This requires higher electricity input to the heat pump, corresponding to an increased exergy demand and consumption, to achieve the same space heating or cooling.

The required exergy input to the system (power plant where the electricity is generated) increased by 14% and 5% for heating and cooling, respectively. Increased floor covering resistance has a similar effect to an increased space heating or cooling load, on the water side of the radiant system while in fact the space heating and cooling loads are not changing.

The floor covering resistance should be kept to a minimum in order not to hinder the performance of the floor heating/cooling and the whole system and to benefit from the low temperature heating and high temperature cooling potential.

ABSTRACT. The foreseen large deployment of renewable energy sources may seriously affect the stability of energy grids. It will be necessary to control energy consumption to match instantaneous energy production. The built-in Energy Flexibility in buildings may be utilized for stabilizing the energy grids and allow for a larger roll out of renewable energy sources as buildings can be controlled in order to shift energy demand in time. The Energy Flexibility of a building is the ability to manage its demand and generation according to local climate conditions, user needs and grid requirements. Energy Flexibility of buildings will thus allow for demand side management/load control and thereby demand response based on the requirements of the surrounding grids. Currently there is no overview or insight into how much Energy Flexibility different building types and their usage may be able to offer to the future energy systems. The aim of the Annex is thus to increase knowledge on and demonstrate the Energy Flexibility buildings can provide for the energy grids, and to identify critical aspects and possible solutions to manage this Energy Flexibility. In-depth knowledge of the Energy Flexibility that buildings may provide is important for the design of future Smart Grids and buildings. The knowledge is, however, not only important for the utilities it is also necessary for companies when developing business cases for products and services supporting the roll out of Smart Grids. It is further important information for policy makers and government entities involved in the shaping of the future energy systems. The paper will discuss the background, the aims and the work plan of IEA EBC Annex 67. The working phase of IEA EBC Annex 67 was started in June 2015 and will last until June 2019. It is the intention that the paper will outline the scene for a session with papers related to IEA Annex 67 written by participants of IEA EBC Annex 67.

ABSTRACT. The cost of locally installed renewable electrical and thermal production systems is dropping rapidly. The most popular technologies include photovoltaics, micro-wind turbines, solar-thermal systems and ground source heat pumps. Increasing popularity of the intermittent sources of renewable energy, such as solar and wind, also creates pressures for higher and more unpredictable fluctuations in the price and primary energy use of centralized grid-provided energy. A local energy management system can be used in order to make full use of these intermittent energy sources and to maximize the utility of local energy storage capacity by balancing the grid interactions to minimize cost or/and the consumption of non-renewable primary energy. This article describes the results of a project that has developed a predictive control method for managing the energy systems of a complex and variable mix of residential energy systems, including local energy production, conversion and storage systems, as well as connections to electric or thermal grids. The prototype system is easily configurable for different system configurations. An optimization program is implemented, which is based on simplified energy flow-based models of components of an energy system for a single-family house, but is also robust enough to adequately represent layered connections to a state-of-the-art stratified heat storage tank, in which heat is consumed from different layers for space heating and domestic hot water consumption. The optimal selection of the system’s parameters by the optimization program is based on looking 24 hours ahead in fixed time intervals (typically 0.1 hours) and selecting a sequence of control parameters such that the system is kept within given boundaries, while minimizing a goal parameter, such as the net cost of energy. This allows the system to take into account not only the system’s current state, but also looks at how the current behaviour of the system affects the constraints at a later time. In a complex system, the number of free parameters can be considerable, and when the selection is made for each time step, the number of possible system states grows exponentially. Instead of a combinatorial approach, the implemented optimization system uses a successive linear programming-based solution that considers the whole 24-hour period as a vector of values, in which there are constraints between the elements of the vector. Using this method, the optimal behaviour can be determined very efficiently, which makes it possible to perform simulated experiments of extensive periods of time. Testing of the energy management system using a simulation model for different cases has provided promising results. In one case, the energy management system was able to change a simulated comprehensive single family house energy system from a yearly cost of 173€ into an income of 30 €. Further method development and testing with a physical emulator system has been planned.

ABSTRACT. The increase of renewable integration is a challenge of balancing today’s power grids and requires new strategies to avoid network congestion. Load shifting and peak shaving have been identified as promising strategies to shape the load and to modify energy consumption patterns of buildings. A key element to change the energy usage of buildings is the application of thermal and electrical energy storages. By nature, buildings offer a great potential for storing energy, either by utilizing the available thermal capacity (building thermal mass) or by adding energy storages (water, ice, phase change materials, thermochemical materials, electrochemical materials etc.). In addition, district thermal energy storage might be used to extend the building demand flexibility. In this study the operational load shaping of office buildings using a water thermal energy storage is investigated. The thermal storage can be a building integrated water storage vessel or a district water storage tank. The objective is to show for different operational conditions (storage energy capacity, storage discharging power, ambient conditions etc.) the amount of energy and power flexibility that can be provided to the power grid while modifying the building demand pattern. Therefore, the study concentrates on a day ahead optimization to find the optimal discharging strategy of the thermal energy storage for peak shaving and load shifting. In particular the study presents a method to change building load profiles from a water thermal energy storage perspective. First, typical load profiles for heavy weight and lightweight office buildings are evaluated describing a base case. Second, a dynamic building model is applied in order to access the zone temperature as a state variable. This approach enables the building model to give and receive feedback within a closed-loop optimization. Third, a dynamic thermal energy storage model is used considering the water storage temperature as state variable. Fourth, various objective functions are defined that intend to shape the load of different office buildings considering peak shaving and load shifting. Fifth, optimization constraints are determined considering weather data, building parameters (comfort bounds, occupancy probability and internal gains) and storage parameters (temperature bounds). Sixth, simulations are performed for different operational conditions. Therefore, stochastic dynamic programming is chosen as optimization methodology that enables the implementation of nonlinear dynamics. A major contribution of this study is to emphasize the increase of energy and power flexibility of office buildings that are connected to a water thermal energy storage. In the full paper, the most important flexibility indicators affecting peak shaving and load shifting strategies are discussed. A method is proposed that can identify the energy and power flexibility for different office buildings and various operational conditions. This method is applicable to the process control of buildings advising the power grid coordinator. The full paper also graphically illustrates the modification of load profiles for various office buildings considering peak shaving and load shifting.

ABSTRACT. The use of thermal energy storage in the thermal mass of a building’s structure is often suggested as a key technology to improve the penetration of renewable energy sources and counter grid stability problems. Therefore a quantitative assessment of the flexibility provided by structural thermal energy storage is a prerequisite to instigate a large scale deployment of dwellings as active storage technologies that can be used in a demand response context. In literature, the benefits and limits of active demand response in a building context is generally assessed by means of case studies. Examples are studies on the impact of demand response for the optimization of the energy use in a smart grid context or for local optimization of the integration of renewable energy sources. To characterize the potential of structural thermal storage for active demand response (ADR) and enable a case-independent evaluation and comparison of different building and storage technologies, a generic, simulation-based, dynamic quantification method is presented in this work. The goal is thereby to demonstrate the impact of dynamic boundary conditions, and therefore the time-dependent nature of the ADR characteristics used to describe the ADR potential of structural thermal energy storage. Specifically in this paper, the available storage capacity (CADR) and storage efficiency (ηADR) are defined as performance indicators for the ADR potential. Using the developed dynamic quantification method, both indicators are quantified for 8 different residential building types covering a wide range of insulation qualities, available thermal capacities and sizes. The available storage capacity and corresponding efficiency, as defined in this paper, allow a comprehensive comparison of the impact of the building design on the ADR potential assuming simplified, static boundary conditions. While such an approach enables a fast evaluation during the design phase, application of the ADR characteristics in practical applications, such as control and optimisation, requires the acknowledgement that these indicators are dynamic in nature. Both CADR and ηADR show significant dependence on solar gains, outdoor temperature variations and occupancy behaviour. Thereby, a reduction of the heat demand during normal operation – when the outdoor temperature rises and solar gains increase – demonstrates that the applicability of structural thermal energy storage using the heating system should be limited to cold periods during the heating season to guarantee high storage efficiencies. Daily variations in CADR and ηADR are found to be mainly induced by occupancy behaviour. In both cases, proper design of the control strategy to anticipate on changes in the occupant behaviour and outdoor climate should be considered. The developed, dynamic quantification method presented in this paper can support the development of such control strategies and aid in the optimisation of energy storage in a demand response context in general.

ABSTRACT. The ongoing development towards electrification of the energy consumption together with large deployment of renewable energy sources creates new challenges of variability and fluctuation of the electricity supply and increases complexity of the network operation. In order to capture all the particularities of electricity demand and on-site generation, e.g. the short-term spikes due use of high electricity consumption appliances such like electric kettle, and get a full picture of network performance, a high-resolution input data are needed. This paper compares the business-as-usual network modeling with modeling when 1-minute domestic electricity demand and generation profiles are used as inputs. The analysis is done with a case study of low-voltage network located in Northern Denmark. The analysis includes two parts. The first part focuses on modeling the domestic demands and on-site generation in 1-minute resolution. The load profiles of the household appliances are created using a bottom-up model, which uses the 1-minute cycle power use characteristics of a single appliance as the main building block. The profiles of heavy electric appliances, such as heat pump, are not included in the above-mentioned model, as they are closely related to the thermal properties of a building. Therefore, two type of single family houses equipped with heat pump are simulated in EnergyPlus with 1-minute time step. The PV generation profile is obtained from a model developed in Matlab environment. In the second part the generated profiles are inputted in a low-voltage network model created in DIgSILENT PowerFactory. By means of employing 1 hour based demand and generation profiles in during dynamic studies, the representation of the local power system performance might sometimes not be as accurate as needed. In the test system employed in this case the simulation indicates that no stress is created in the grid. The loading of the transformer and power lines is 65% and 41%, respectively, which is below the limit of 80% of available capacity. The maximum voltage drop is 5.1% thus with the maximum allowed deviation of ± 10% and ± 6% according to standards and common practice, respectively. The same investigation, but with 1-minute input data, shows that the transformer is overloaded by 2% and the minimum voltage level is 0.922 % [p.u], which is below limits of common practice grid operation. When adding on-site PV on 50% of buildings, the loading of the transformer and power lines is reduced in the summer time to 58% and 51%, respectively. However, the power lines are stress with bi-directional power flow. The results indicate that the business-as-usual approach to network modeling is not sufficient to capture the characteristic spikiness of the domestic load profiles and on-site generation. Hence the network overloading and high voltage deviations are not visible and the control strategies may be wrong.

ABSTRACT. In the following years, an increased share of the renewable energy sources (RES) in the grid is expected, bringing up the challenge of variability and fluctuation in the energy supply. Even though the energy balance between production from RES and demand might be covered on an annual basis, there might be periods of the year when the renewable energy cannot match the demand. There is thus a need for storage solutions, in order to optimise the use of fluctuating energy sources. Some investigations pointed out the potential of the building thermal mass to store this excess energy in form of heat. A few pilot projects tested demand-side management of the heating need in residential buildings (e.g. Voltalis, Greenlys). The response of the users to the activations were relatively positive, and the effect could be measured at the grid level. However, the periods of activation were relatively short (between 20 minutes up to 2 hours). The objective of this study is thus to define how long the activation can last without compromising the comfort of users. Using Building Energy Simulation tools, the potential of two residential buildings with different levels of insulation and air-tightness has been assessed. This wide range of thermal properties gives the global performance of the existing building stock, and does not only focus on state-of-the-art buildings. These buildings are located in the west part of France (Rennes). A price signal has been used as an indicator of the availability of electricity. This application is limited to one type of grid, which corresponds to the spot market price observed in the French electricity market in 2012. During the time of high-price, the set-point is decreased by 2 K, whereas the set-point is increased by 2 K during time of low price. Different periods of modulations have been tested: 20 minutes, 1, 2, 4, 6, 10 and 18 hour(s). A better understanding of the dynamic behaviour of a building has been achieved in this paper. The autonomy of a poorly-insulated building is relatively short, whereas passive houses have a long time constant. This characteristic implies differences in the control strategy in order to make use of the flexibility potential without compromising comfort. The maximum time of activation varies from a couple of hours for a poorly-insulated building up to 18 hours for a well-insulated building. From the grid perspective, a high flexibility potential has been observed: it is possible to move the heating need from hours with a high spot price to hours with a low spot price.

ABSTRACT. As part of the Energy Transition initiative announced in 2010, the German government plans to increase the share of renewable energies, most notably wind and PV power, in the electricity mix to 80% by the year 2050. These ambitious plans present a major challenge, as the power output of wind and PV plants is highly volatile. One approach to attenuate these fluctuations and reduce the demand for electrical storages and energy conversion processes is demand-side-management using heat pumps. According to this concept, operation of heat pumps is shifted to the most suitable times of the day when there is a high relative availability of electricity (i.e. low residual load, high fraction of renewables in the electricity mix), whereas operation is avoided during times of high relative demand for electricity. In order to cover the time offset between heat/cold generation and heating/cooling load, thermal energy is stored in technical (water) storages or the thermal mass of the building itself, e.g. using thermally activated building systems (TABS). While previous analyses suggest that TABS is in principle well suited for use as heat storage, it is unclear how governing parameters such as the thermal comfort requirements, the dimensioning of the heat pump, and the integration of local PV production affect the load shifting potential and suitability of buildings with heat pumps for demand-response. In this contribution, a numerical study on different heat pump operation strategies in a nearly-net-zero-energy office building equipped with photovoltaics and TABS as a heat distribution system is presented. The focus of the evaluation is the energy exchange with the electric grid and impact on the energy system. In the analysis, the grid interaction is analyzed using supply and load cover factors and a novel method based on the absolute and relative Load-Grid Matching Coefficients (GSCabs and GSCrel) [1]. The GSC weights the electricity consumption or feed-in with a grid-based reference quantity (here: Residual load, fraction of wind and PV in the electricity mix) expressing the availability of electricity at any given time. At the same time, the impact of load shifting on the efficiency of the heating system and the thermal comfort in the rooms is analyzed. The simulations are carried out via co-simulation with Python and Dymola/Modelica via PyFMI. Conventional control strategies for the heat pump are compared with a new energy management algorithm, which prioritizes the use of locally produced electricity and excess electricity from the grid, but ensures that comfort requirements are not violated. The results show that the largest part of the load shifting potential lies in the heating and shoulder season. Furthermore, the load shifting potential of heat pumps can be increased significantly if a small increase in thermal comfort violations is allowed.

[1] K. Klein, R. Langner, D. Kalz, S. Herkel, H.-M. Henning: Grid support coefficients for electricity-based heating and cooling and field data analysis of present-day installations in Germany. Applied Energy 162 (2016), pp. 853-867.

ABSTRACT. Introduction The concept of model predictive control (MPC) is to use a model of the building dynamics together with predictions of weather and occupancy to operate heating, ventilation and air conditioning (HVAC) systems more energy-efficiently and to provide flexibility to the energy grid through demand responses. A critical task when utilizing MPC is to obtain reliable information of occupancy. The reason is that the thermal indoor climate of a building and, consequently, the need for HVAC energy is highly affected by the internal heat gains generated by the metabolic rate of the occupants and occupants’ use of electrical equipment. Furthermore, using HVAC systems to maintain thermal comfort in unoccupied building zones is a waste of energy. MPC must therefore include information regarding the current occupancy and predictions of future occupancy when planning the operation of the HVAC systems.

Method This paper proposes an occupancy model based on a two-state inhomogeneous Markov Chain. The purpose of the model is to handle the stochastic nature of occupants and thus make better predictions of occupancy. The occupancy model has the ability to adjust to sudden changes in room usage, as it is interconnected with real-time sensor-data based occupancy detections. The proposed occupancy model is integrated in an economical MPC framework with the objective to minimize the total energy cost of the heating system, constrained by the requirement of maintaining thermal comfort when the room is predicted to be occupied. Furthermore, the proposed occupancy model and the associated economical MPC framework have a temporal resolution of 5-15 minutes, hence, enabling the operation of the heating system to handle fluctuating occupant presence.

Results and Discussion Simulations concerning the control of the heating system for a one-bedroom apartment are used to illustrate the efficacy of the method. The simulations are run for four different occupancy profiles, which diverges greatly due to the stochastic nature of the occupants. The occupancy profiles are established based on real-world CO2-measurements from four independent apartment. The CO2-measurements are transformed to binary occupancy schedules, which is assumed to be the ground truth. Since each occupancy profiles differs significantly, the simulations stresses the occupancy model.

Conclusion Compared to a traditional thermostat and a controller that utilizes static schedules of the expected occupancy, the evaluation of the proposed method suggest a great potential for cost savings. Furthermore, thermal comfort violations is reduced. The simulation results emphasize that occupant presence affects the energy consumption greatly. This makes the integration of occupancy information a high priority task, when optimizing the operation plan for HVAC systems. The proposed occupancy model is simple to implement in a MPC framework and is therefore a good solution for application of MPC in real buildings.

ABSTRACT. INTRODUCTION In the pursuit of increased energy efficiency and demand-side flexibility, a number of model-based control schemes are beginning to emerge in building energy management systems. One way of establishing a building model for model-based control is to use a statistical method. A statistics-based building model is derived from measured data from the actual building. This data must represent the thermal dynamics of the actual building to obtain a model which is useful for model-based control. It is therefore current practice to run a series of artificial temperature fluctuations over several days – so-called excitation signals – in the building to generate data that reveal the thermal dynamics of the building. These temperature fluctuations might be uncomfortable to the occupants of the building. The aim of the analysis presented in this paper is therefore to investigate various excitation signals in terms of the trade-off between occupant comfort during excitation period and the accuracy of the resulting building model. The analysis also evaluates the building models in relation to their intended end-use as the predicting part of an economic model predictive control (EPMC) algorithm.

Method The analysis is carried out as a co-simulation between MATLAB and Energy Plus. A one-bedroom dormitory apartment is used as the case study. Excitation signals with different strength of temperature fluctuations are evaluated. Stochastic noise is introduced in the signals to resemble the nature of occupancy-related heat gains. A total of five different noise realizations per excitation signal are evaluated to make the analysis more robust.

Results The output from the simulations shows that increasing the strength of the temperature fluctuations in an excitation signal generally only leads to slightly better building models. Furthermore, the model quality has only a very small influence on the performance of the EMPC algorithm.

Discussion The analysis is based on simulations. The advantage is that this allows direct comparison of models generated with different excitation signals but the exact same noise. This is interesting from a theoretical point of view when developing appropriate excitation signals. However, replicating the intention of this analysis in a full-scale experimental setup might reveal other issues to consider when working in the real world, especially regarding occupant acceptance of fluctuating temperatures in the excitation signals.

Conclusion The results of the analysis suggest that there is no need to include highly fluctuating temperatures in excitation signals to derive building models which is suitable for EMPC. On the contrary, it seems counterproductive to the public acceptance of EMPC to have highly fluctuating temperatures in excitation signals as they are likely to decrease occupant comfort during the sometimes rather prolonged excitation periods.

ABSTRACT. INTRODUCTION Energy consumption for household HVAC constitutes a large demand response (DR) potential if it can be made flexible e.g. through the concept of model predictive control (MPC). A common way to motivate consumers for DR is through price-based DR programs. Most studies on price-based DR only use the electricity market price while ignoring any taxes and fees that the consumer is also charged. Taxes and fees, however, often constitute the bulk of the total electricity price and may therefore affect the DR. This paper investigates the impact that different tax and fee structures have on the DR potential of applying MPC for space heating and takes offset in the current Danish electricity tax and fee structure.

METHOD The study is based on simulations where an economic MPC is used to control an electric baseboard heater in a one-bedroom dormitory apartment. The simulations were conducted as co-simulations between EnergyPlus and MATLAB which was coupled by the Building Control Virtual Test Bed (BCVTB) software environment. The current Danish tax and fee structure and alternative tax and fee structures are used as input to the MPC to investigate how taxes and fees affects the potential for cost savings, reduction in CO2 emissions and load flattening.

RESULTS AND DISCUSSION The results show that taxes and fees can have a significant impact on the DR and the current Danish tax and fee structure reduce the potential of cost savings and load flattening. Simulation results also indicate that it is possible to construct alternative dynamic taxes that improves the DR potential rather than reducing it. This might be valuable input to a political discussion on future electricity tax and fee structures.

CONCLUSION The conclusion is that the DR potential calculated solely with respect to the electricity market price may lead to misinterpretation of the actual potential in a supply systems where the price is subject to taxes and fees.

ABSTRACT. Laboratory facilities are energy intense building types due to the vast amounts of 100% outside air required. With today’s concerns over high energy expenses and providing a better indoor environment, increasing new and existing lab facility energy efficiency has become a critical challenge.

The primary reason behind many labs’ high energy expenses is the minimum ventilation requirements that often dominate their use of outside air. This presentation will present a proven demand based control solution to this problem. In this approach that is now recommended by the ASHRAE handbook, rather than use a fixed air change rate of 6 to 12 ACH, real time measurements of the lab indoor environmental quality vary the air change rates from as low as 2 to 4 ACH to upwards of 8 to 16 ACH based on the lab room’s air cleanliness. By safely cutting the lab air flows by as much as 50% or more for about 98% of the time, this approach is often cited as the single largest energy conservation approach for many lab facility designs. Furthermore in new designs, significant net reductions in first cost may also be achieved through reductions in the HVAC system sizing. Finally by significantly increasing air flows when contaminants are sensed, improved Indoor Environmental Quality (IEQ) can be achieved.

This presentation will describe this ventilation control approach plus discuss one technology used to implement it cost effectively. Additionally, the results will be shown for the largest study ever done of lab IEQ conditions covering over 1.5 million hours of lab operation. Furthermore a variation of this concept will also be discussed that is used with other facility types such as office buildings, educational facilities, public assembly buildings such libraries and student centers, and healthcare facilities.

Multiple case studies will be highlighted such as a retrofit of the 2006 R&D Lab of the year at Arizona State University where this concept is saving over $1 million annually in energy costs. Commercial building projects will also be discussed such as the Bank of America Building in NYC, one of the world’s largest LEED Platinum skyscrapers and the LEED Platinum renovation of the ASHRAE Headquarters in Atlanta, Georgia. Finally, a highly sustainable, “near net zero carbon” lab project at Masdar City in Abu Dhabi, UAE will also be discussed.

ABSTRACT. Cleanrooms with turbulent mixing ventilation for dilution of airborne particle contamination require substantial quantities of supply air in order to maintain the requested ISO-class. The air change rate is about 20 to 160 1/h which is significantly more than in generally ventilation systems. The positions of supply air diffusers and extract air openings have a significant influence on the ventilation effectiveness in these rooms. A usual way to access the ventilation in these cleanrooms is a ceiling-supply and ceiling-return air system. This leads to small distances between the supply and extract air openings. That causes significant direct short circuit flows that reduce the ventilation effectiveness. In this paper, the influence of the position of the extract air openings is investigated. In addition to change the supply air distribution curtains around the inlet openings are tested. In order to validate the numerical model, the global air change efficiency and the velocity field in the room was measured in an experimental setup in the research cleanroom at the Hermann-Rietschel-Institute. The CFD-studies determine the influence of the distance between supply and extract air openings and the supply air guidance system are performed. The goal is to reduce the amount of direct short circuit flows and increase the ventilation efficiency. In return of the better dilution of airborne particle emissions the air change rate could be reduced for higher energy efficiency.

ABSTRACT. Introduction The article is focused on indoor environment in a kitchen of a family house. A kitchen equipment consists of gas stove and gas water heater. The schedule is following: a regular everyday use of gas stove and a gas water heater for cleaning the dishes. The study aims at the ventilation issues during a 3 day period of time in summer conditions. The available ventilation appliances are: digestor and window opening. The family house has been reconstructed. It has new wooden air tight windows and thermal insulation. It is investigated if all pollutants produced by these gas appliances are ventilated away. The study investigates: if the ventilation strategies are sufficient for air exchange, if occupant`s behavior has a significant influence on ventilation, if the ventilation is efficient enough to get rid of all pollutants emitted by gas appliances. Methods Following methods were used to investigate indoor environment in the kitchen. Measurements were taken of carbon dioxide, carbon monoxide, TVOC and formaldehyde during summer conditions. The pollutants were measured in 3 selected standpoints. The standpoints were chosen to determine air flows in a room. Temperature and relative humidity were measured in the kitchen and outside in the stairs. A tracer gas was used to calculate air exchange in time when every window and door is closed and when there is some sort of ventilation schedule. The occupants wrote down their schedule of a kitchen use and behavior – the schedule of their ventilation habits, their presence in the room, their activity – for better comprehension. Standard ventilation rates were listed and ventilation rates through building envelope were calculated according to SF6 concentration decay. Ventilation rates during usual use of kitchen were calculated. Balance calculations were taken in order to find out the real ventilation rate needed during the occupied hours and occupants activities in the kitchen. The balance was calculated from gas appliance output and its conversion to carbon dioxide and to ventilation rate of fresh air. Results According to the measured values the measured concentrations of pollutants are higher than it is required especially during the time when gas appliances are used. The calculated air change through the building envelope with closed window and door from SF6 concentration in three standpoint was calculated as -0, 04; -0, 07 and -0, 07. The required ventilation rate changes according to the occupant´s activity. Discussion The ventilation rate is not sufficient during times when gas appliances are being used. The pollutants weren’t able to be ventilated away sufficiently. Different measured values for three different places make a good question of how one correct point should be chosen and how the exact concentration should be measured. Conclusion The solution would be a special device an indicator. This indicator should be able to measure concentration of the following pollutants – carbon dioxide, carbon monoxide - for the kitchen use. For other rooms purposes it should work as indicator which says – when and how much ventilate the room. This solution should reflect the ventilation need during presence and activity of occupant.

ABSTRACT. INTRODUCTION: Exhaust gas emissions caused by the combustion of gas water heaters make worse hallway air quality because the exhaust outlets of gas water heaters are typically installed in the hallway of apartment buildings in Japan. To improve this problem, adequate natural ventilation planning is needed considering various factors, such as characteristic of exhaust gas, width of the hallway, opening size, etc.The purpose of this study is to predict the air quality in the hallway where gas water heaters are installed. METHODS: First, we construct the model that general hallway where gas water heaters were installed in Japan. We measure the CO2 concentration in the model with gas water heater to verify the jet characteristic of exhaust gas. From these results, we reproduced the actual phenomenon in computational fluid dynamics (CFD). We evaluate the CO2 concentration in the model with various factors, such as characteristic of exhaust gas, width of the hallway, opening size by CFD. Finally, we make new installation standards of the hallway where gas water heaters are installed in Japan. RESULTS AND DISCUSSION: The CFD results show good agreement of air quality in a hallway of an apartment building where gas water heaters were installed. Indoor CO2 concentration is standardize less than 1000ppm by the Building Sanitation Management Standards, Japan. The measured results showed that the CO2 concentration in the model was measured less than 1000ppm. From CFD results, When opening size of hallway is large, air quality in a hallway is unaffected by characteristic of exhaust gas and width of the hallway. CONCLUSIONS: We constructed the general hallway’s model in Japan. The CFD results show good agreement of air quality in a hallway of an apartment building where gas water heaters were installed. It was confirmed that air quality in a hallway satisfy Japan standard if hallway opening size were taken into consideration based on the CFD results.

ABSTRACT. A new principle of ventilation system, so called Temperature-Controlled Air Flow (TAF), designed for operating rooms was examined using computational fluid dynamics technique. TAF system is a hybrid of the two well-known mixing and vertical laminar airflow ventilations. The exploration used a validated numerical calculation schemes (CFD approach). A Realizable k-ε turbulence model was applied to map the airflow field, and a Lagrangian particle-tracking model was used for the phase of particles. Airborne particle concentrations were reported in surgical area. The results showed that the TAF system is able to provide a clean environment safe enough for surgical procedures. This system has about the same performance as the well-known laminar airflow ventilation system.

ABSTRACT. Several gas explosions [1-3] had occurred in residential buildings in big cities in the Asia-Oceania areas, including a very big gas explosion in a garage of about 200 m2 for repairing liquefied petroleum gas (LPG) taxis in Hong Kong in April 2015. This gas explosion in a garage not only damaged the building structures, but also killed the owners [3] staying inside. However, the cause of explosion is unknown. Another possibility of having explosion due to flammable clean refrigerants [4] including LPG will be studied. A taxi might have 0.5 kg of refrigerant HFC134a (R134a) stored in the air-conditioning unit. Explosion can result from such a small amount of flammable gas.

The transient gas explosion pressure has to be better understood for protecting firemen during operation. The explosion pressure should not exceed 21 kPa or about 0.21 bar to avoid serious damages to the building as suggested [5]. Approximate amount of LPG involved in that explosion in a garage was estimated using empirical equations reported in the literature [6].

Based on information on the case of explosion in that garage taken out from government website [6], simulation by Computational Fluid Dynamics will be reported in this paper.

Results on the amount of LPG required to generate 21 kPa in that 200 m3 garage will be predicted. A reasonable estimation will be having 3 kg or 3.9 kg of LPG involved in the explosion to give adequate high pressure rise.

Acknowledgement

The work described in this article was supported by a grant from the Research Grants Council of the Hong Kong Special Administrative Region for the project “A study on explosion hazards of clean refrigerant propane leaking from air-conditioning units in small commercial flats” (PolyU 152034/14E) with account number B-Q42U .

References

1. W.K. Chow, “Gas explosion in residential buildings to watch”, Department of Building Services Engineering, The Hong Kong Polytechnic University, January 2015. Available at: http://www.bse.polyu.edu.hk/researchCentre/Fire_Engineering/Hot_Issues.html 2. South China Morning Post, “Firemen fight for lives after gas blast”, 23 November 2014. 3. South China Morning Post, “Three killed in Wong Tai Sin blast”, 27 April 2015. 4. The Standard, “21 hurt in lunch blast”, Hong Kong, 10 January 2013. 5. C.G. Buckland, “Explosions of gas layers in a room size chamber”, Chemical Process Hazards VII – Institution of Chemical Engineers, p. 289 (1980). 6. Lands Department, http://www1.map.gov.hk/gih3/view/index.jsp

ABSTRACT. Introduction Since the epidemics of SARS, a number of outbreak studies have provided probable evidences for the airborne route transmission and proposed several airborne control measures [1]. In the existing investigations of the airborne disease transmission, the multi-zone model has shown its simplicity and accuracy [2, 3]. To evaluate the effectiveness of different airborne control measures, we integrated the multi-zone modelling method with the Wells–Riley equation, revisited and examined the largest nosocomial SARS outbreak in 2003 in Hong Kong.

Methods In the study, we divided the ward into 6 zones and assumed that the bio-aerosols concentration in each zone was uniform. Bio-aerosols containing viruses from the index patient were thought to be transmitted between zones due to the airflows through each opening. Neglecting the influence of outdoor wind on the indoor environment, we considered the airflow as a result of thermal buoyancy and mechanical ventilations. By solving the mass balance equations of airflow and the conservation equations of energy and bio-aerosols, the airflow rates and bio-aerosol concentrations were acquired. Therefore, the exposure dose for susceptible in different zones could be calculated and according to the Wells-Riley equation, the corresponding infection risk were predicted. The infection risk distributions under different conditions, namely various ventilation rates, filter efficiencies, and quanta generations, were compared to evaluate the relative effectiveness of different airborne control measures.

Results The result showed a reasonable agreement between the results from the multi-zone method and those from the outbreak data and CFD methods. With higher ventilation rates, the infection risk was reduced. As shown in Fig. 1, when the filter efficiencies increased, the infection risk decreased and the reductions were more evident in distant zones. The control of quanta generation was found to be more effective when the quanta generation was lower.

Conclusions From the results, conclusions could be summarized as follows: • The multi-zone method integrated with the Wells-Riley equation was applicable to evaluating the role of airborne route of disease transmission. • Increasing the ventilation rates and filter efficiencies was meaningful to weaken the air transmission of disease to distant regions. • The control of quanta generation was more effective for normal index patients compared to super-spreaders.

References [1] Li, Y., et al. (2005). Role of air distribution in SARS transmission during the largest nosocomial outbreak in Hong Kong. Indoor Air 15(2): 83-95. [2] Li, Y., et al. (2000). Prediction of natural ventilation in buildings with large openings. Building and Environment 35(3): 191-206. [3] Chen, C., et al. (2011). Role of two-way airflow owing to temperature difference in severe acute respiratory syndrome transmission: revisiting the largest nosocomial severe acute respiratory syndrome outbreak in Hong Kong. Journal of the Royal Society Interface 8(58): 699-710.

ABSTRACT. Introduction Nosocomial infections have become a severe health issue due to its prevalence and mortality [1]. The transmission process of influenza is poorly understood [2]. The relative importance of different transmission routes remains controversial and therefore the most appropriate control strategies are usually difficult to decide. In this study, we made use of a newly-developed multi-route disease transmission model to predict the infection risk of different transmission routes of influenza in a hospital ward.

Methods In the new transmission model, three transmission routes, namely the airborne route, close contact route and fomite route, were considered. With regard to the long computational time period, the index patient was assumed to be a steady source. As for the airborne transmission route, the ward was divided into several zones and the exposure dose for the susceptible in each zone was calculated based on a multi-zone airflow model. In the close contact model, an idealized respiratory jet was assumed to exist when the index patient carried out respiratory activities, and the exposure dose caused by direct inhalation of droplet nuclei or large droplet deposition on the mucous membranes was respectively calculated. The fomite transmission model associated all representative environmental surfaces in the ward with human touching behaviors and predicted the exposure doses caused by touching mucous membranes with contaminated hands. With the Wells-Riley equation, the relative importance of different routes was quantitatively compared in the form of infection risk. The new model was validated against the epidemiological data from a seasonal influenza A outbreak in a general medical ward at Princes of Wales Hospital (PWH; Hong Kong) in 2008 [3].

Results According to the simulation results for 1000 times, the airborne route contributed 18% about to the infection, and the infection risk decreased as the distance increased; the close contact route contributed about 63%, and only those assumed to have close contact with infectors were possible to get infected; the fomite route contributed about 19%, and the infection risk distributions were relatively uniform except those adjacent to the virus source. With higher close contact frequencies and longer durations, the close contact route contributed more to the infection and brought more random to the distribution of the infection risk.

Conclusions The results suggested that close contact transmission control measures were the most meaningful to prevent the transmission of influenza, and proper ventilation system design and enough surface cleaning could be effective invention methods for outbreaks.

References [1] Mayon-White, R., et al. An international survey of the prevalence of hospital-acquired infection. Journal of Hospital Infection. 11 (1988) 43-48. [2] Killingley, Ben, et al. Use of a human influenza challenge model to assess person-to-person transmission: proof-of-concept study. Journal of Infectious Diseases (2011): jir701. [3] Wong, Bonnie CK, et al. Possible role of aerosol transmission in a hospital outbreak of influenza. Clinical infectious diseases 51.10 (2010): 1176-1183.

ABSTRACT. Diffuse ventilation works through the pressure chamber above the acoustic suspended ceiling to uniformly distribute the supply air to the occupied zone. This, in effect, increases the thermal mass of the room because the upper slab of the room no longer is isolated from the occupied zone. In this study, the cooling potential of a diffuse ceiling ventilation system is investigated by experiments focused toward characterizing the convective heat transfer of the plenum. The heat transfers are quantified from four different air flow rates, the temperature of the air supplied to the plenum and the mean surface temperature, i.e. the total heat transfer coefficient of the plenum. The established heat transfer coefficient is used for analysis of the cooling performance of the system in dynamic building simulation program which showed that during peak summer days, the scenario with ventilated plenum would exhibit temperatures in the occupied zone approx. 1-1.5 °C lower than the baseline with unventilated plenum. In conclusion this study disclosed the mean heat transfer of the plenum with an inlet jet of approx. 1.2-0.4 m/s and temperature differences of 0.5-4.5 °C and showed that ventilation supply through the plenum can be used to augment the night cooling potential.

ABSTRACT. Natural ventilation was considered to be efficient to reduce airborne infection due to its high ventilation with energy saving manner. However, natural ventilation relied on ambient weather and inpatients personal control. This paper presents long term field measurement indoor CO2 concentration and temperature in a general hospital ward in Nanjing. The hospital was central corridor, which is not recommended by WHO guideline but very widely used in Chinese hospital. CO2 was used as tracer gas to indicate the ventilation rate and indoor air quality in hospital ward. The results show that in transition period, CO2 concentration is much lower in transition seasons than that in heating and cooling seasons. Inpatients and visitors activities also influence CO2 concentration in different periods in a day in hospitals. And the relationship between temperature and the habits to open the windows is also reported. The results showed that natural ventilation need improve in heating or cooling seasons to reduce airborne infection.

ABSTRACT. Natural ventilation for reducing airborne infection has gained extensive attention due to its high ventilation rate with low energy consumption. Properly designed natural ventilation system in hospital environment is of great importance to both patients and health care workers. World Health Organization (WHO) proposed 5 types of natural ventilation systems in the hospital. In this paper, the potential of natural ventilation systems for reducing airborne infection was investigated by applying a multi-zone model MIX. The results showed that single-side corridor type, wind tower type and chimney type are effective in reducing infection while central corridor type should be avoided because it is easy to cause contamination in a downstream room. The courtyard type may lead to pollutants re-entering and thus its openings should be designed with great care.

ABSTRACT. The aim of this paper is to investigate the effect of the particle source location on contaminant distribution in a displacement ventilation system with varying air supply settings. This study investigates two different supply locations (perforated floor and wall diffuser) and two supply air flow rates (40 m³/h and 250 m³/h) with three different particle source locations at a buoyant source (bottom, top, overall). Contamination dispersion patterns and ventilation effectiveness were evaluated by means of computational fluid dynamics. The results indicate that the particle source location has no significant impact with a suitable combination of diffuser location and supply volume flow rate. In this case, efficient removal of contaminants is achieved with both positions of the supply diffuser. However, the supply location has significant impact when the air is supplied through wall-diffusers at a high volume flow rate. The air flow pattern around the source is influenced, resulting in a polluted occupied zone and thus in a poor ventilation effectiveness.

ABSTRACT. Implementation of EU directives has forced EU member countries to revise the building regulations related energy efficiency. In Finland the process started in 2013. The regulations in the revising process include also those dealing with indoor environment and ventilation. The demand to revise regulations offered also an opportunity to evaluate the performance and applicability of current regulations in practice. The Finnish Ministry of the Environment (in charge of building regulations) invited the Finnish Professional HVAC organization (SuLVI) to make a study on the quality and needs for improvements of the regulations. The work was done by a questionnaire send to the members and through interviews of experts representing various professions in construction process. The focus on the study was on factors affecting indoor air quality and energy efficacy of ventilation. In general the professionals were content with the scope and structure of the current regulations. However, the study revealed several important issues which should be changed in the revising process of regulations. Finland has used the material emission labelling system to reduce the building related emissions since 1995. The minimum ventilation rates have been for some years 6 l/s per person. Majority of the experts considered this as appropriate number of the minimum ventilation rate in the future as well. The investigations revealed that in many cases the recommended values (l/s per m2) are too high or too low. This may lead to bad air quality on some cases and excess energy use in other cases. Too high ventilation rates were given for corridors, restaurants, cafeterias, supermarkets, department stores, shops, hotel rooms, auditoriums, halls, washing rooms. The total air flow was also too high for day care centers, and for some apartments. Too low ventilation rates were given for elderly home, classrooms, fitness centers, sports halls, residential kitchen hoods, operation rooms in hospitals, and for some apartments. Specifically for apartments more accurate guidelines are needed to match the ventilation for the occupancy of apartment. The results also showed that some changes are needed to avoid the IAQ problems, one of the most important was the reduction the maximum negative pressure difference over the building envelope, the current value of 30 Pa should be reduced to 5…10 Pa. This would reduce the flow of pollutants trough building envelope to indoors. This is getting more important when building envelopes are getting more tight (max leakage 4 m3/h per m2 envelope area at 50 Pa) and at the same time kitchen hoods, central vacuum cleaners and fireplaces are installed and used. The measures to improve the energy efficacy included several technical items like: mandatory requirements for demand controlled ventilation, more stringent requirement for ventilation heat recovery, extended use of regenerative heat recovery, more stringent requirements for systems seasonal SFP etc.

ABSTRACT. Ventilation in buildings is extremely important to create a healthy environment and prevent mold growth. The new building regulations demand an air‐tight building envelope in order to improve its energy efficiency. Therefore, infiltrations and natural ventilation are often not sufficient to provide an adequate air change and mechanical ventilation becomes necessary. The main goal of this study is to evaluate the energy demand of a decentralized ventilation system with respect to a centralized ventilation system in a typical resi-dential building using dynamic simulation in TRNSYS environment. German and Ital-ian climate conditions as well as building insulation values of both countries were con-sidered. Ventilation flow rates are according to the European Standards. Occupancy patterns were assumed for each room. The results indicate that in colder climate the energy demand for heating and cooling does not change sensibly with the two configurations, while the centralized sys-tem has an electric energy consumption 50 to 70 percent greater than the decentral-ized system. In warmer climates, the former system requires nearly 30 percent more energy for heating and 30 percent less for cooling than the latter system. Primary en-ergy consumption is always less with the decentralized system. This is due mainly to the greater amount of air processed by the centralized sys-tem in order to provide the requested air quality in each room. Although the decen-tralized system seems to require less energy, other factors (e.g., installation and O&M costs) could influence the convenience of this configuration.

ABSTRACT. In order to minimize the energy costs and at the same time create a healthy indoor environment in public buildings such as offices and schools, the idea of an eco-friendly breathing zone ventilation using textile ducts was developed. The main goal is to lower the total air volume by delivering fresh air directly into the breathing zone of the room occupants. By reducing the air volume it is possible to save money as it is not necessary to ventilate the entire room, but only to ensure a good air quality in the breathing zone. This new idea was accomplished while using tailored textile ducts with a specifically invented hole pattern so that an even air flow could be obtained with a guidance beam cut directly into the fabric. At the Technical University of Denmark (DTU) this new system was tested in their laboratories using manikins that produce pollutants to obtain a real life situation. By applying this new way of thinking it was established that it is possible to reduce the air volume by up to 25-30% compared with conventional ventilation systems. Further, it was discovered that both the cleanliness of the delivered air and the systems's ability to remove contaminated air from the breathing zone was better than that of conventional ventilation systems even when this new breathing zone ventilation system was operating at a lower air volume than conventional systems.

ABSTRACT. Diffuse ceiling ventilation (DIFCV) is an air distribution system where fresh air is supplied to the room from a pressurized space above a suspended ceiling (plenum). Research suggests DIFCV as a promising candidate for fulfilling future energy and indoor climate requirements compared to conventional ventilation systems. The DIFCV principle has been studied for various types of conventional suspended ceiling. However, more studies are needed to fully understand the mechanisms of the concept. The purpose of this paper is to report on an experiment investigating the ability of a non-perforated suspended ceiling system solution to remove exces¬sive heat loads from a room without causing thermal discomfort when functioning as a diffuse ceiling inlet.

The experimental investigations were conducted in a full-scale test room where a full suspended ceiling solution was installed. The test room was equipped as a single-person office and in turn four dif¬ferent summer (cooling) scenarios were established with different excessive heat loads (10, 30, 60 and 100 W/m2). These heat loads were removed using a fixed tempera¬ture difference of 10 K between supply air and the air temperature in the occupied zone and varying supply air flow rates. For each scenario the thermal indoor environment was evaluated and a description of the room air distribution provided together with calculation of the temperature efficiency of the ventilation system as a measure of mixing in the space. Smoke experiments were conducted for the scenario with the highest heat load intensity to visualize the room air distribution. Furthermore, pressure loss investigations were conducted for the suspended ceiling system solution and for a single ceiling tile.

For all four scenarios all criteria for indoor climate category A in CEN 1752 were fulfilled except the criterion regarding maxi¬mum mean air velocity where the scenario with 60 W/m2 fulfilled category B while the scenario with 100 W/m2 exceeded the criteria for category C. However, none of the scenarios exceeded the draught rate criteria for class A. The vertical temperature profiles showed almost no temperature gradient in the room in all scenarios and the temperature efficiency was close to 1.0 indicating a high degree of mixing in the room. A pressure drop between 1 – 5 Pa across the suspended ceiling solution was measured. The ceiling system as a diffuse inlet system is thus an energy-efficient solution compared to more conventional ventilation inlet systems. The pressure drop across a single ceiling tile was much higher than the pressure drop across the complete ceiling system suggesting that the gaps be¬tween the ceiling tiles in the mounting system is the primary air path from the plenum to the room. This was later supported by smoke experiments where microjets were observed to be forming along the gaps.

ABSTRACT. Currently, 82% of global energy demand is produced by non-renewable energy sources, which significantly increase CO2 emission and global warming. Buildings are responsible for approximately 40% of global energy consumption, where nearly 43% of this energy is consumed by residential heating and cooling purposes, forcing building sector to significantly reduce its energy demand. Developed passive strategies over thousands of years have great potential for widespread use to decrease dwellings’ energy demands. Particularly as a most common, economic and applicable strategy natural ventilation via windows, has a huge potential to reduce buildings cooling load. This study empirically evaluates the wind-driven ventilation effect of a common traditional Turkish architectural element called Cumba in low-rise dwellings to investigate the functionality and applicability of this historical solution to discover the potential for decreasing modern domestic energy demand. A benchmark building selected as a result of case study over 111 different existing traditional Turkish architectural samples. Building with Cumba and without Cumba compared with different conditions different. It was observed that Cumba enhances the room’s average indoor air velocity by 138%, and average ventilation rate by 224% for different wind directions and velocities. Similarly, room’s average indoor air velocity and ventilation rate increased by 125% and 276% when different window opening are utilized in the building. Outcomes of this study clearly shows the huge potential of Cumba elements on the enhancement of low-rise buildings’ natural ventilation.

ABSTRACT. The demand for high energy efficiency of office buildings has increased the use of demand based HVAC systems. In addition to the traditional control of cooling water flow rate based on room temperature in the air-water HVAC room units, the most energy efficient method has been to use variable ventilation airflow rates. One advanced demand based use of radiant and convective HVAC room units would be the utilization of building thermal mass to reduce cooling design power. This could further increase the energy efficiency. This paper presents energy simulation case study of a simplified office building with active chilled beam and chilled ceiling with mixing ventilation. It compares the cooling load and cooling energy consumption in design day and shows the potential for energy efficiency.

The case study office building consisted of four typical office rooms of which external wall and window was directed to south, north, east and west. Office building was located in middle European, temperate climate and had good energy efficient building materials and window characteristics. The effect of thermal mass was studied by having in heavy case all surfaces of room with concrete (room without suspended ceiling), and in light case all surfaces except floor with gypsum board (room with suspended ceiling). Modern active chilled beam and chilled ceiling system with mixing ventilation were selected with realistic performance data. Energy simulation was done with state of the art dynamic simulation software, simulating indoor climate conditions and cooling system operation during cooling design day. HVAC system operating schedule was following: ventilation was only used during office hours, and cooling water system was operated 1) only during office hours, 2) all the time with same room temperature set-point and 3) all the time with room temperature set-point lowered by 3 degrees during night time.

Both active chilled beam and chilled ceiling system with mixing ventilation were maintaining all office rooms in design room temperature. The chilled ceiling system had more limited cooling capacity, whereas active chilled beam was able to provide cooling also with higher inlet water temperature. The highest cooling demand of 81 W/m2 was in the east office room of light building with both HVAC room units in operating schedule 1. When building was changed to heavy, the highest cooling demand was dropped by 16%. By using operating schedule 2, the highest cooling demand dropped in heavy building to about 60 W/m2 (25%) with both HVAC room units. With operating schedule 3, the biggest reduction in design cooling demand to about 40 W/m2 was found with chilled ceiling. The design cooling demand for central cooling system could be dropped by 36% by using operating schedule 3 during design days. The design day cooling energy consumption was increased due to this 7%.

The presented reduction of the cooling design power by controlling the operating schedule during cooling design days can bring savings in cooling system dimensioning, and possibility to dimension HVAC room units with higher cooling water inlet temperature and reach energy savings from efficient utilization of alternative energy sources.

ABSTRACT. INTRODUCTION: Active chilled beams are used to simultaneously ventilate and cool or heat indoor spaces. The characteristic feature of these devices is the entrainment of room air due to turbulent mixing at the jet edges of multiple small, high velocity primary air jets inside the device. Room air, so-called secondary air, is drawn into the device passing a heat exchanger. The thermal power of the active chilled beam is determined by the entrainment ratio, meaning the ratio between the volumetric flow rate of the entrained secondary air and the supplied primary air. The entrainment ratio is mainly determined by geometrical influences such as the nozzle design and the internal wall contour of the device as well as the flow resistance of the heat exchanger. However, the flow pattern is also influenced by the fluid’s local density distribution which is variable when the active chilled beam is operated under non-isothermal conditions, as in the cooling or heating mode. In this paper, the influence of non-isothermal boundary conditions on the entrainment behavior of an active chilled beam is investigated experimentally by measuring the entrainment rate and the thermal power of the chilled beam simultaneously. Measurement data will be used to gain information on how higher water supply temperatures require optimized beam geometries, i.e. when using geothermal heat sources for indoor cooling.

METHODS: Measurements were conducted using an experimental setup containing a typical active chilled beam for office applications mounted in a suspended ceiling environment. Primary and secondary air flow rates were determined using the differential pressure method. A dedicated air duct was built to ensure that only the measured secondary air is supplied to the active chilled beam with an evenly distributed velocity profile. Thermal power was supplied to the beam’s heat exchanger using an internal hydraulic system connected to an external hydraulic heat supply. Water temperatures of the internal hydraulic system are adjusted accurately by using a magnetically actuated mixing valve. All set values are controlled automatically in order to obtain good reproducibility of the measurements. Measurement uncertainty for the overall entrainment rate was determined to be below two percent of the measured value. Flow fields were measured downstream the beam outlet using 2D2C particle image velocimetry (PIV).

RESULTS AND DISCUSSION: Results show high sensitivity towards variations in the isothermal boundary conditions, e.g. upstream secondary air flow resistances or chilled beam placement relative to the ceiling. Furthermore, sensitivities are identified under non-isothermal boundary conditions, e.g. variations of the heat exchanger supply temperature and water volumetric flow rate, provided that the thermal power of the chilled beam is kept at a constant value.

CONCLUSIONS: It can be concluded that the experimental setup makes it possible to measure small variations in the entrainment rate of an active chilled beam over time with high accuracy and reproducibility.

ABSTRACT. With the aim of exploring the optimal installation position of sensors and range of temperature control for active chilled beam (ACB) in an office room with the liquid cooling air-conditioning system (LCAC), the coupled simulation of the computational fluid dynamics (CFD) and the network model of building energy is used to examine the indoor thermal environment and ON/OFF time cycle of chilled water supply for the ACB in different location sensors and range of temperature control. In this context, the contribution ratio of indoor climate (CRI) of heat sources are calculated by using CFD, coupled with the network model, so that the temperature fluctuation over time at any indoor positions can be predicted. A case study involved different location sensors and range of temperature control schemes was carried out in this paper. The results showed that with the range of control temperature narrowing around the set temperature, the ratio of stopping time of the ACB chilled water supply increased, especially when the sensor was installed at the position around human bodies. Meanwhile, the differences of indoor energy balance between cases did not show obvious change, but the cold storage of chilled water existing in ACB’ coil was utilized efficiently if the stopping time closed to 4 minutes . Therefore, many required volumes of chilled water for ACB were able to be saved without increasing indoor cooling demands.

ABSTRACT. Coughing and its importance for spreading of respiratory infectious diseases have been confirmed in many previous studies. The dispersion process of respiratory droplets released by coughing of a patient in a hospital ward was studied using computational fluid dynamics (CFD) simulation. Two patients with a parallel bed arrangement occupied the examined ward. The maximum dispersion distances in time under ward ventilation conditions were studied. Relatively realistic three-dimensional thermal manikins were considered to simulate the patients. A coughing velocity profile is used to simulate a time-dependent cough with total duration of 0.4 s. The results indicate that the transport characteristic of droplets due to coughing is highly influenced by the size of droplets. The effects of gravity or inertia on small droplets (> 40 μm) are negligible and the indoor airflow field mostly influences their transport. Although, droplets of < 40 μm significantly affected by gravity and soon fall as the strong coughing airflow field become weaker.

ABSTRACT. Indoor air contaminants pose serious threats to human health and one of them is airborne microorganisms including viruses, bacteria and fungi. For healthcare facilities or hospital wards, exposure to these contaminants may lead to infection. Previous studies have shown that building air conditioning or ventilation systems can transport the contaminants throughout interior spaces. To reduce the risk of cross-infection indoors, current technologies include HEPA and ultraviolet disinfection are commonly used and implemented into HVAC systems. However high initial and operation costs of HEPA may not suitable for general purpose buildings and high UV dose may lead to emission of byproduct ozone. Corona discharge based on unipolar ionizer is another means for removing aerosol particles in indoor environments. Previous experimental results reported that cell membrane of bacteria was ruptured and torn when it exposed to surroundings with negative ions, however, very few studies were conducted in ventilation ducts and particularly where the negative ionizer is installed. Thus the objective of this paper is to study the disinfection effect for bioaersols when the negative ionizers were installed in a duct system. Three different scenarios for ionizer installation were studied in this paper: one negative ionizer was installed near the inlet (denoted as case 1); one negative ionizer was installed near the return vent (case 2) and two negative ionizers were both installed at inlet and return vent (case 3). A mathematical model was developed to predict the distribution of negative ions as well as the bacteria. The corresponding 3D room model was established by ANSYS ICEM with duct system directly connected with the room. Structured mesh was generated to discrete the fluid domain into a number of finite volumes. In order to model the negative ions and transport of microorganisms, the potential, electrical field, negative ion and bacteria concentration were implemented into FLUENT as user scalars. These equations were numerically solved by an implicit segregated solver. The simulation results showed that the bacteria were disinfected when negative ions were presence. The disinfection efficiency relates to the concentration of negative ions. The best scenario was in case 3 where the pollutants were totally removed after 200s. Case 2 was the worst one since the bacteria was not removed from the indoor space (the concentration was still 0.5 after 200s), and for the Case 1, even though the bacteria was removed from the indoor space, the duct system was still filled with bacteria. In order to reduce the risk of cross-infection in a ventilated room, 3 different scenarios of negative ionizer installations were configured and numerically simulated. The bacteria were removed when the negative ionizer was installed inside the duct system. The negative ionizers both installed near the inlet and outlet gave better distribution of negative ions and disinfection efficiency for bacteria compared with other cases. Thus for real application, it is recommend the negative ionizer should be installed both inside the inlet and the outlet.

ABSTRACT. Recently, energy saving has advanced, even in hospitals and medical centers. With the aim of further energy savings than by using only commonplace techniques, in these buildings planning has been done to reduce environmental load using their specific climate properties. Main climate properties considered include (1) severe cold in winter, (2) the use of abundant underground energy, and (3) the length of low-rainfall periods and sunshine hours. Considering these factors promises to reduce CO2 and promote energy conservation. This paper grasps the practical use situation of the air-conditioning system and confirms the effect by a measurement investigation. Located in Saku City, Nagano Prefecture, in Japan's Shinshu region and making use of vast and lush grounds, the investigated building is organized into a clinic and a ward. The building started full-fledged operation in March 2014. It is a large-scale hospital responsible for emergency medical care in the region. Because of the importance of maintaining air balance, adoption of a natural ventilation system in the hospital is difficult. However, the building allows natural ventilation because it is provided with a buffer space between the inside and the outside. During winter, the buffer space is utilized as a heat-insulating layer, and planning prevents propagation of outside cold. From the results of actual natural ventilation measurements, night purge was performed in summer and natural ventilation was being done in the daytime in autumn. From correlation of the air change rate with the outside environment, it was found that the system uses wind pressure ventilation of outside air as the driving force, which was confirmed to be influenced by the outside wind direction. From the results in the thermal environment of the whole measurement, the corridor had become a thermal buffer zone between the outside and in-room environments. For the most part, PMV in the buffer space was comfortable. Heat exchange was performed by introducing outside air into a cool heat trench. In summer this was at most 120 kW for the precooling effect, and in winter this was at most 50 kW of preheating effect. From the above results, this corridor can be used as an environmental buffer space. It is able to operate while maintaining the comfort of the thermal environment. Absorbing energy effectively from the outside environment is thought to have contributed to energy saving. While efforts for extreme reduction of environmental load are difficult in a hospital facility, their effect was clearly demonstrated.

ABSTRACT. Building Information Modelling (BIM) applications and process has the potential to transform the way buildings are designed, constructed and operated by offering significant productivity benefits. The UK Government has mandate the use of BIM on large public projects from 2016. Despite many investigations into BIM adoption and its benefits, there is still a lack of clarity as to how the AEC/FM industry is coping with this change and many remain sceptical of its potential benefits. This paper aims to understand the value of current BIM models to the operations and maintenance of the facility by investigating the BIM workflow processes in one particular SME operating within the UK’s AEC industry. The paper provides an in-depth review of industry-wide, national perspective on trends and progress in BIM awareness, adoption & implementation with focus on key barriers to its adoption. The literature review informed the subsequent parts of the research investigating the information and related exchanges pertinent to the operations and management of the facility via a case study. The case study presented investigates the current status of BIM processes by evaluating the BIM model handover processes and its value to facility management (FM) as well as of the current perceptions and attitudes towards BIM. Given the nature of the business enterprise chosen for this case study, the employees issued with the questionnaire were considered appropriate as the characteristics of their profession exemplify the majority of different professional roles in the AEC industry. The questionnaire was broken down to 4 parts with a total of 40 questions. The first section focused on questions with regards to patterns of BIM use particular on the respondent’s engagement with collaborative working and the general requirements for design applications within the organisation to enable the handover of post-construction information. The second part looked at the development and use of BIM objects. The third part had a list of questions associated with the BIM benefits with added focus on their interactions with clients/owners while the last part concentrated on key barrier affecting the adoption, implementation and use of BIM within the organisation. The literature review offered strong evidence to suggest that BIM can increase productivity, efficiency, quality and sustainability via effective collaboration and communication of stakeholders in construction projects. In FM particularly benefits can be summarised to include improved preventive maintenance, space management, energy efficient initiatives, information and life-cycle management. It is important to recognise that the value of BIM to FM is determined by the value of information contained in a BIM model at handover. A significant finding from this case study is however that the given practice indicated that they rarely ever handover BIM models post-construction to clients/owners due to the lack of demand for it. This further suggests that that the current BIM specifications for facility handover information are not creating opportunity to extract additional value out for operations and management beyond the scope of the requirements of design and build.

ABSTRACT. INTRODUCTION

The quasi-steady state method presented in the EN ISO 13790 should be implemented assuming, for the parameters a0 and τ0, specific values depending on the climate and the building typology. Since national standards do not often set the most suitable values to be used, the method is usually implemented with reference values. The results are therefore quite different from those of detailed dynamic simulation methods. This work shows the results obtained implementing the simple hourly method (5R1C) with those coming from a detailed dynamic simulation software. Furthermore, the possibility of using a simplified set of climatic data is explored. The aim is investigating the use of dynamic simulation tools when the climatic conditions are not known in detail. This could be useful for locations with inadequate climatic database, as well as to predict the heating and cooling demand of buildings from weather forecast.

METHODS

The calculation procedure of the simple hourly method provided by EN ISO 13790 has been implemented in Matlab and then tested according to EN ISO 15265. The study case presented in this standard has been considered and the results obtained in terms of annual energy need for heating and cooling have been compared to the reference values provided by the standard. In this way the accuracy of the model and its compliance with the standard have been checked. Then a simplified method to generate weather data has been defined. The simplified dynamic calculation method and the simplified weather conditions have been tested and the results obtained in terms of annual heating and cooling net energy demand have been compared with those obtained using a detailed simulation software, TRNSYS, and TMY climatic data. With the purpose of checking the accuracy of the simplified methods for energy demand calculation, the following set of simulations has been carried out for each of the 4 considered locations (Rome, London, Stockholm and Ouagadougou): • TRNSYS simulation with real TMY weather data; • TRNSYS simulation with simplified weather data; • R-C model with real TMY weather data; • R-C model with simplified weather data.

RESULTS AND DISCUSSION

The accuracy of the simplified weather generation model has been evaluated, along with the accuracy of the simplified R-C model of the building against a detailed calculation model, the accuracy of the simplified weather generation model when applied to the simplified R-C model and the overall accuracy when applying the simplified method of the building and of the weather generated model against a fully detailed method with real weather conditions. The relative difference for both annual heating and cooling net energy demand is smaller than 10% in all the cases.

CONCLUSIONS

In this research activity the use of a simplified method which reproduces the weather data of a typical day in each month has shown to be appropriate to evaluate the monthly heating and cooling demand of a building. The results obtained coupling these weather data with a simplified dynamic calculation method (5R1C model) are quite similar to those coming from detailed calculation methods and detailed weather data.

ABSTRACT. The Energy Performance of Buildings Directive (EPBD) issued by the European Council forces an increased energy efficiency of buildings in Europe. Beside the reduction of required heating energy, this directive aims also towards ventilation and cooling. The method described in FprEN 16798-13 (“Cooling Generation”) is implemented into a computer code and validated against the results of the spread sheets provided with the standard. This code allows performing annual energetic simulations in order to obtain the energy efficiency by means of the individual energies (electrical energy for a compressor, heating energy for desorption, auxiliary energy for heat rejection and sensors&actors ...). The influences of various system components, control schemes, as well as part-load and temperature levels are tested and their results displayed. These results support a detailed discussion of the advantages and disadvantages of the system, control, and part-load schemes, which can also be of use for the design of cooling systems.

ABSTRACT. Building Information Modeling (BIM) is a platform with great potential to increase the efficiency of building design. The utilization of BIM has gained popularity among building designers during the last few years, and today it is widely used within design of commercial buildings in Norway. BIM is continuously developed and consequently new application areas of the platform arise. A prominent feasibility to increase the efficiency, and potentially the quality, of HVAC design is to use calculation applications implemented in the BIM-based design tools. Today a number of different calculation applications exist, but these are seldom used in the design process and some are not validated.

The purpose of this paper is to investigate if the design tools with BIM facilities, which are already commonly used in design of HVAC systems, can be applied to carry out heating and cooling calculation at room level and to evaluate the quality of such calculations.

Heating and cooling calculations were conducted using the following programs: Revit MEP, MagiCAD Comfort and Energy and IDA ICE. In addition heating calculations were carried out using the Norwegian standard NS 12831 «Varmesystemer i bygninger – Metode for beregning av dimensjonerende effektbehov». The calculation model is based on two open plan offices located in a museum building in Oslo, Norway.

The investigation indicates that the calculation applications within the evaluated BIM based design tools are in positive progress, but there are still some limitations with respect to utilizing the tools in the design of HVAC systems. Concerning the heating calculation, the greatest limitations are found in relation to the external wall area, cold bridges, heat loss to the mechanical ventilation system and internal heat losses. Concerning the cooling calculation, the limitations are regarded the use of solar shading, internal heat load, mechanical ventilation system and the possibility to analyze the results.

Generally, the study suggest that even though heating and cooling calculations are more easily accessible when using BIM-based design tool, it is even more important that HVAC engineers are the one conducting and controlling the calculations and its results. This is due to the simplifications in the input and output data and the complexity in the calculation methods. If HVAC engineers are not the one doing the calculations, there is a great risk of making mistakes in the calculation and thus design errors when designing HVAC system.

ABSTRACT. BIM Building Information Model or Modelling connects many different information systems from various actors during the building construction process with each other in one easily accessible and understandable model. BIM assures an effective and efficient building construction process by reducing failing cost and reduces the use of materials by so called clash-controls. More and more buildings and infrastructural works are completed with help of BIM and materials, energy, time and money are saved by doing so. But why not use BIM for the exploitation phase of both new and existing buildings? By connecting the BIM model with the other exploitation information systems as Facility Management Information Systems (FMIS), and Building Information Systems it’s possible to create an easily accessible and understandable building and operating information management tool. Furthermore using BIM during the exploitation will increase the BIM market. This paper makes clear that BIM an make a big difference in the quality of the exploitation and operation of buildings, by helping creating a better and comfortable indoor climate while reducing energy losses and costs. Facility Managers should be the owners of this “exploitation and operation BIM” and have to know which information they must extract from the BIM and how to manage this information system. Another benefit will be time savings, and thereby money savings, because searching, reconstruction and updating building information again and again is not needed anymore. The paper also discuss some of the problems with the implementation and use of such a BIM.

ABSTRACT. Introduction Current links between BIM and EPG only use the building’s geometry from the BIM. The applied installation concept is entered (once again) into the EPG-simulation tool or the information is linked to the space as an installation concept. In both situations the technical installation data in the BIM can deviate from the entered data used in the EPG calculation. In this situation two streams of information are in use in one BIM. This way the BIM misses its target, being designed as a tool for clear communication

Method This article contains a case study in which the application is limited to the ventilation system of the building. It is assumed that the heating and cooling systems can be worked out in a similar manner. The elaboration of the case study approaches the input requested by Vabi as close as possible. From the case study a number of points arise that require attention in the elaboration of this study. A major concern is the phase in which the EPG is normally drafted. It is common for this calculation to be carried out in the pre-design phase and not in the final design phase like this study does.

Results and discussion The goal was the transfer of data from a BIM to a EPG-simulation. This data-transfer has the following advantages: - Save time: faster calculations and a shortened iteration-time; - Consistent data: a data link between BIM and EPG; - Reusable data: data stored in template / content The research focuses on the data link between the BIM and the EPG-simulation. Herein IFC is used as a universal data transfer format. The main question was as follows: How can an EPG-simulation be integrated in a BIM, using the data exchange format IFC? From this study it can be concluded that by applying IFC as universal data transfer format between to software programs (in this study Revit and Vabi) a working data link can be established. This gives the possibility to replace Revit by different design software. Realization of this data transfer should eliminate the process of entering the same data multiple times in different programs. Conclusion Completing the data transfer using the methodology described in this study can provide a solution for a number of applications. This study builds a bridge between the BIM and simulations, and between building services and Design and Decision Support Systems.

ABSTRACT. Annex 60 is developing and demonstrating new generation computational tools for building and community energy systems based on the non-proprietary Modelica modeling language and Functional Mockup Interface (FMI) standards. The anticipated outcomes are open-source, freely available, documented, validated and verified computational tools that allow buildings, building systems and community energy grids to be designed and operated as integrated, robust, performance based systems with low energy use and low peak power demand. The target audience is the building energy research community, design firms and energy service companies, equipment and tool manufacturers, as well as students in building energy-related sciences. Currently fragmented duplicative activities in modeling, simulation and optimization of building and community energy systems that are based on the Modelica and FMI standards will be coordinated. Tool-chains will be created and validated that link Building Information Models to energy modeling, building simulation to controls design tools, and design tools to operational tools. Invention and deployment of integrated energy-related systems and performance-based solutions for buildings and communities will be accelerated by extending, unifying and documenting existing Modelica libraries, and by providing technical capabilities to link existing building performance simulation tools with such libraries and with control systems through the Functional Mockup Interface standard. Demonstrations will include optimized design and operation of building and community energy systems. Activity 2.3 focuses on the use of models to augment monitoring, control and fault detection and diagnostics methods. This promises to detect a degradation of equipment efficiency over time because measured performance can be compared to expected performance at the current operating conditions. Furthermore, use of models during operation allows operational sequences to be optimized in real-time to reduce energy or cost, subject to dynamic pricing. This paper will offer an overview of the work carried out within this IEA Annex 60 Activity 2.3 both in terms of approach and case studies with a particular focus on Modelica models use during operation for model predictive control.

ABSTRACT. The life cycle assessment (LCA) methodology has over the past decade gained increased importance due to both EU and national focus on resource use and resource conservation. For the European building sector, the life cycle perspective is a prevalent theme of the standardised approach to sustainability assessment of buildings as introduced by the CEN/TC 350 standards. Furthermore, the life cycle perspective plays a prominent, although still not fully clarified, role in the Construction Product Regulation. In Denmark, LCA on buildings forms part of the 2014 national building strategy where the general concept of sustainability of buildings is presented as one of five focus areas. Political initiatives following this strategy has resulted in clarification of a suggested methodological approach to building LCA, several research projects, as well the launch of a freely available software tool, the LCAbyg. Based on these recent developments in the sectoral use of LCA, this paper presents a life cycle energy assessment of a typical Danish single-family house in terms of operational energy use as well as the embodied energy within the materials and technical systems of the building. The study looks in detail to the distribution of renewable and non-renewable primary energy uses from single building elements as well as from the different life cycle stages. The study furthermore compares operational and embodied energy of three typical solutions for the single-family house to comply with the operational energy performance requirements set by the 2010 regulations, the low energy requirements of 2015 as well as the building class 2020.

ABSTRACT. The aim of this study is to investigate embodied energy from certified sustainable buildings in Denmark and to analyse the technical systems’ share of this embodied energy. Furthermore, the aim is to identify possible deficiencies and improvements of the method descriptions applied for the building LCA in order to properly include the technical systems and their share of the embodied energy of a building’s life cycle. A more comprehensive analysis of five building cases was performed in order to investigate which technical systems were in fact included in the building LCA and to identify which technical systems were omitted in the building LCA. The study showed large variation in technical systems’ share of embodied energy, or from 1 to 40%. The review also showed a large variation in how thoroughly technical systems were included in the LCA studies. On the basis of this study it is recommended that a more detailed description is provided on how technical equipment should be included in building LCA, and that improvement of the data availability for technical equipment is prioritised. Furthermore, better descriptions of design choices are needed to supplement the LCA calculations in order to improve the conformity check of performed LCAs.

ABSTRACT. Annex 57, EBC, IEA deals with methods for evaluating embodied energy/CO2eq of buildings, in order to find better design and construction solutions of buildings with less embodied energy and CO2eq. This paper focuses on the main outcome of Annex 57, which are the worldwide embodied CO2 emissions for construction and the introduction of two effective measures to reduce embodied energy/CO2eq. Total embodied CO2 emissions due to construction was estimated to be 20.3% of the total worldwide CO2 emissions. In particular, fractions of embodied CO2 emissions are higher in developing countries and often exceed CO2 emissions due to the building operation energy. Embodied energy in the construction phase is increased 20% and embodied CO2 emissions, 32% by increasing building life time. However, annual embodied energy is reduced to 72% of the reference building and embodied CO2 emissions, to 79%. On the other hand, the additional cost is increased 9% of the original cost of the building. Embodied CO2eq due to insulators is equivalent to 2% and refrigerator, equivalent to 10% of the building’s embodied CO2 emissions in office building. In a residential building, the impact of fluorocarbon gases used in insulators is the same or greater than the embodied CO2 emissions at the time of construction, and embodied CO2eq due to fluorocarbon gases used in refrigerants accounts for 22% of embodied CO2 emissions at the time of construction.

ABSTRACT. A large number of simulation tools are available for the estimation of a building’s energy consumption (such as TRNSYS or ENERGY Plus ). These tools may produce yearly profiles of the energy needed by a building, for heating, cooling, lighting and ventilation as well as for hot water and electrical appliances. Nevertheless, several studies show that there are significant discrepancies between measured and calculated energy consumptions by these simulation tools. It is therefore necessary to reliably estimate the fluctuations in energy consumption. The stochastic variables linked to the climate and to the behaviour of the buildings’ occupants have important influences on those fluctuations. While climate data are available by measures with a correct accuracy, corresponding data linked to the occupant in all its stochastic activities are still lacking. The aim of this work is to evaluate how the existing occupancy stochastic models can contribute to a better accuracy in the prediction of energy consumption. This paper proposes also to evaluate how simple measures can contribute to improve the models of occupancy. The algorithms tested and presented concern the occupancy hours and occupancy rate. To achieve these objectives and to calibrate the tested models, the occupancy and energy are monitored on an existing office building. The occupancy monitoring results are presented and compared to the tested models. The impact of occupancy on the predicted energy consumption is then evaluated on the office building and compared with the monitored energy consumption.

ABSTRACT. Under the EPB Directive, EU countries have implemented systems to include energy performance certificates in advertisements for the sale or rental of buildings. The certification process is based on a 4 hours building inspection followed by a calculation process to estimate the level of primary energy consumption. Calculations are based on standard occupancy patterns. They do not take into account the real energy consumptions that are difficult to integrate in the assessment because the behavior of occupants can deviate strongly from the standard assumptions. On the other hand, rigorous full test scale experiments and careful modelling studies were conducted by scientists in order to validate their simulation models and explain the discrepancies observed between theoretically predicted and measured building responses. Such experiments provide well documented data sets regarding building physics and benchmarks for modelers. The rising question is: how could those full scale experiments inspire us in order to improve the EPB evaluation process by integration of data measured on site? What are the most relevant data to collect through a less intrusive collection process? To answer that question, an observation of indoor temperature profiles was conducted during summer 2014 in a passive house located in Belgium. The observation includes periods with and without occupancy. Occupants were asked to describe their behavior regarding windows opening, closing of external blinds, opening of internal doors. Electric devices were listed and the electricity consumption profile was analyzed in order to disaggregate that profile into the different uses. A first simulation reveals overestimation of calculated indoor temperatures. An energy balance of the building is established using measured indoor temperatures and climatic data as input to the simulation. A calibration is performed focusing on the results related to sunny and unoccupied periods. The calibrated model yields an estimation of the Building Heat Loss Coefficient. The comparison with the calculated value of the HLC confirms that the house reaches the passive standard. Attempts are made to confirm the value obtained for the HLC by considering only the measurements performed during occupancy periods. The strong influence of the assumptions related to occupants’ behavior in summer is confirmed and recommendations are made to better describe that behavior in terms of use of mechanical ventilation, windows opening and use of external blinds. One way to bridge the gap between research and practice, as far as estimation of the building envelope Heat Loss Coefficient is concerned, is to perform measurement of indoor temperature profiles during unoccupied periods when the solar heat gains are sufficient to reach significant indoor-outdoor temperature differences. The estimation of HLC from the observed indoor temperature profiles during sunny periods where the building is occupied is trickier. It can be improved by the collection of relevant data related to the occupants’ behavior. Both strategies are ways to improve the EPB evaluation process by integrating site measurements data.

ABSTRACT. One of the most discussed issues in the design community is the performance gap. In this research we investigate in a novel way whether part of the gap might be caused by the modelling literacy of design teams. 108 building modellers were asked to comment on the importance of obtaining and using accurate values for 21 common modelling input variables, from U-values to occupancy schedules when estimating annual energy demand by dynamic simulation. The questioning was based on a real domestic dwelling for which high resolution energy data had been recorded. A sensitivity analysis was then conducted using a model of the building by alternating one parameter in each simulation. The effect of each alteration on the annual energy consumption in the model was found and a ranked list generated. The order of this list was then compared to that given by the modellers for the same changes in the parameters. A spearman-ranking value of 0.43 was found and an R2 value of 0.28, which clearly indicates little correlation between which variables were thought to be important by the modellers and which proved to be. In addition, there was no correlation between modellers, with many ranking some parameters as important that other thought irrelevant. Using a three-part definition of literacy it is concluded that this sample of modellers, and by implication the population of building modellers, cannot be considered literate.

ABSTRACT. Measurement and Verification (M&V) is critical for understanding the energy performance of a building and for confirming projected energy savings from implemented retrofits. However, measuring and analyzing all possible energy related points in order to get the complete energy picture of the whole building can be very cost prohibitive. Therefore, this paper demonstrates the utilization of sensors and Internet of Things (IoT) to identify and quantify the most relevant data points for energy M&V. Particularly, it details the approach in placing these sensors subject to the constraints in an operational office building, challenges encountered and early results from the data collection. The findings reveal that measured floors have consistent patterns and similar sensor readings; comparisons were done not only across different floors, but within a floor (spatially) as well as on temporal (time) scale; based on the parameter readings, spatial and temporal zones that displayed similar patterns were identified.

ABSTRACT. This paper presents the results from the work carried out in Greece in order to quantify the differences of calculated and actual heating energy use in Hellenic residential buildings. The approach is based on the exploitation of data from thousands of energy performance certificates (EPC) to derive empirical adaptation factors, defined as a ratio of actual to calculated energy use that could then be used to adjust predictions for large building stocks. The work is complemented by evidence from field surveys on occupant behaviour and the actual energy use before and after the implementation of energy efficiency measures in dwellings. Data from the EPCs reveals that the average actual primary energy use is 44% lower than the normative calculations. Findings from the field surveys of occupant behavioural changes in the operation of space heating systems confirm the deviations of calculation assumptions from actual operating conditions. For example, only 17% of single-family and 10% of multi-family houses have operating hours close to the assumed 18-hours used in the calculations, while the heated floor area is only 33% and 43% respectively, compared with the total heated floor area considered in the calculations. Field data on actual energy use before and after common retrofit actions provide additional insight. For example, weather adjusted actual primary heating energy savings are about 16% by installing double glazed windows and 18% by replacing an oil-fired boiler with a new natural gas unit and 33% with a heat pump.

ABSTRACT. For the assessment of the energy use of buildings in a regulatory context (EPBD) in Flanders (Belgium), a quasi-steady-state, sequential HVAC subsystem calculation approach is used that decouples the building from the system. Thermal losses are calculated separately for each subsystem using tabulated efficiencies. Several researchers have demonstrated however that the efficiency of the HVAC system depends on the building and the mutual interaction between the subsystems. Simultaneously, some of the tabulated data are oversimplified and inaccurate. The aim is to evaluate the accuracy of this simplified calculation of the energy use for heating in school buildings.

The energy use for heating is calculated in a reference elementary school building in Flanders (Belgium). Building characteristics like insulation level, thermal mass, glazing properties, WWR, air tightness level, orientation and shading device are varied. The heating system comprises a traditional hydronic heating system with a modulating, condensing gas boiler and low temperature radiators controlled by thermostatic radiator valves. Balanced mechanical ventilation including heat recovery is foreseen. On the one hand, the energy use for heating is calculated as a function of the energy demand and the overall system efficiency based on EN 15316. The emission losses are included as a heat emission efficiency (EN 15316-2-1). The simplified approach for calculation of the distribution efficiency in EN 15316-2-3 and the boiler efficiency method for determining the generation efficiency in EN 15316-4-1 are used. On the other hand, integrated building and HVAC system simulations are performed in TRNSYS to study the dynamic interaction between both the building and heating system, and between the various subsystems. Results of the simplified method in EN 15316 are compared to the integrated building and system simulation results.

The results compares the effect of the part load ratio on the emission, distribution and generation efficiencies between EN 15316 and TRNSYS. The overall system efficiency is slightly overestimated by EN 15316 especially for low part load ratios because the standard estimates a constant value while simulations show decreasing subsystem efficiencies when part load ratios are lowered. A good fit is found between the statically and dynamically calculated generation efficiencies. The overall effect on the annual energy use is limited. Moreover, the impact of the building characteristics on the overall efficiency is studied. The control efficiency depends on the building’s characteristics while the impact of the building on the generation and distribution efficiency is less significant.

The use of an annual overall efficiency to express the energy use for heating as a function of the heat demand is shown to be a good simplified calculation approach in school buildings. A more accurate tabulated overall system efficiency based on the results of the integrated building and HVAC simulations is however necessary. The impact of the building on the overall performance of the heating system is limited and can be reduced almost completely to variations of the control system efficiency.

ABSTRACT. There often is a significant difference between predicted energy performance of buildings and actual energy performance once buildings are operational. Actual occupant behavior is often different from the assumptions made in the design stage, and this is regarded as one of the main reasons for the performance gap. The diversity in occupants' sociological and behavioral characteristics must then be taken into account when predictions are undertaken, in order to determine confidence intervals of the expectable performances. Software tools must then be made available to design firms, letting them generate statistically representative sets of occupants and plausible activity and appliance use scenarios. Here we introduce two tools developed at CSTB, named Qiriel and Croniq, focused respectively on statistical generation or inference of dwellings, appliances and households, and on stochastic simulation of occupants' activities and the implied appliances activation and power consumption. They are built upon French national databases on households and time use surveys. These tools enable their users to generate occupancy, activity and power consumption profiles for specific sociological profiles or for representative sets of households. The obtained sets of series can then be used to determine median and extreme configurations of building usage, and the implied range of building performances. Such tools can then be useful at the building design stage, in order to evaluate how robust a building can be when confronted to a large variety of usage patterns.

ABSTRACT. Introduction Energy Performance Contracting (EPC) has shown to be a successful vehicle towards a low-carbon economy. However, apart from the need for building energy savings, the building industry has also come aware of a recurring mismatch between predicted- and in-use energy consumption of buildings. EPC can help to reduce this performance gap, but the gap is also attributed as a significant barrier for large scale implementation of EPC. This study investigated the risks in energy performance contracting caused by the performance gap.

Method A literature review was performed to get insight in the state of the art knowledge on the causes and magnitude of the performance gap, causes were identified based on the stage in the building project in which they are created. Five different projects of the international engineering consultancy Royal HaskoningDHV were then evaluated to determine the industry’s current ability of predicting building energy performance and the consequences this has for energy performance contracting. The importance of the risks involved by predicting energy performance is evaluated by means of a risk assessment for EPC-projects.

Results and discussion Results of the internal project evaluation confirm what was found in literature; on average the building thermal energy demand was 1.5 times higher than predicted in the design. Comparing these results with an EPC-project business case shows that a mismatch of 50% in building energy consumption is crucial for the profitability of energy performance projects. Although the risk on energy performance is significant, the risk assessment shows that EPC-projects are characterized by a large diversity of significant project risks.

Conclusions The results on project evaluation indicate that energy performance predictions get accompanied by a large uncertainty, which is generally not quantified in the prediction. Integrating uncertainties on energy performance in current practice risk management for EPC-projects is therefore required to ensure sound business-cases for all stakeholders.

ABSTRACT. INTRODUCTION The European Directive 2010/31/EU (EPBD recast) on the energy performance of buildings establishes the target of nearly zero energy buildings (nZEB) for all new buildings and major renovations of existing buildings by the end of 2020. The present paper investigates the accuracy of the quasi-steady state method, according to the Italian technical specification UNI/TS 11300, in predicting high performance buildings’ energy consumptions. Both the terms of the building energy balance and the simplified dynamic parameters are assesses by comparing the simplified model with dynamic numerical analysis. CASE STUDIES The two calculation models are applied to some real low energy buildings that are representative of the Italian building stock. The envelop U-values are assumed as complying with Italian official nZEB requirements. Weather data from many Italian locations, two inertial mass configurations and different system operating schedules are considered. RESULTS and DISCUSSION The comparison between the dynamic and static calculations for low energy buildings’ energy performance assessment reveals some discrepancies: the quasi-steady state model generally overestimates the energy need for space heating and underestimates the energy need for space cooling; the gaps are bigger both among various Italian locations and inertial mass configurations than different system operating schedules. The reasons of this gap are discussed in the paper. CONCLUSIONS It is highlighted that in some boundary conditions, national regulations should introduce the dynamic numerical analysis as reference calculation model.

ABSTRACT. Energy calculations have for a long time been a controversial topic as building owners do not necessarily achieve the promised energy savings after a building upgrade, but is this due to incorrect calculations or rather the evidence of misunderstandings in the communication?

In Denmark, the innovation network for sustainable construction, InnoBYG started work on a Danish sector guide for the calculation of actual energy consumption in relation to upgrading of buildings. The focus was to make a common guide for energy calculations that can be used by consultants performing calculations. The guide should help to ensure more uniformity in calculations. Furthermore, the aim was to highlight the influence of uncertainties related to the calculation. This should ensure a transparent and comparable communication of the calculation assumptions, the result and the associated uncertainty of the energy calculation for building owners and developers.

This paper describes the process that leads to the sector guide and briefly explains the content in both the technical guide and the communication paper. Finally the paper discusses some of the known dilemmas related to the measured energy consumption compared with the estimated energy demand by calculation. The paper concludes that the result of an energy calculation should not be given as a single figure but rather as a spread between the best and worst case for the assumed conditions. Finally, a brief update on current actions is given related to the sector guide for calculation of actual energy consumption.

ABSTRACT. Introduction

Following on from the Europe-wide iSERVcmb IEE Project, this paper examines the implementation of an Operational Data approach to help manage a University Estate. The paper explores the benefits the approach brings to understanding the Estate, its Services and the most promising potential areas for investing money, time and effort to achieve lower utility use.

Methodology

The paper is based on a mixed methods approach, using quantitative based approaches for the measurable aspects of the study such as room areas, energy consumption, services components, etc., mixed with qualitative descriptions of the activities serviced in the buildings and the approaches taken to transcribing the information on the existing buildings, meters and components into the online application. The findings and results are illustrated via a Case Study approach.

Results and Discussion

The implementation observations and data outputs for the Estate buildings described according to the iSERVcmb approach are discussed. The discussion includes common issues, the findings to date from a section of the Estate, and the reaction from the Estates team responsible for energy and sustainability. The steps to describing the Estate are considered in terms of time taken, effort involved in obtaining the data, and ongoing approaches to keeping the data current. The results show that all buildings were capable of being fully described at a level of detail that enabled the following to be derived: • An understanding of the key elements of the Estate and its energy operation • An understanding of the physical area and activities served by individual utility meters and building services components on the estate • Production of tailored energy consumption benchmark ranges for each component, system, site and building on the Estate, based on the iSERVcmb methodology • A first discussion of the practical use of Operational Data to operate and maintain an Estate from Overview through to Detail.

Conclusions

The results show that using an Operational Data approach in a large estate helps to improve existing operating procedures and to underpin new investment and decision making. The results also show the wide range of consumptions being achieved in buildings with near-identical function and design, and their potential savings by reference to the bespoke energy benchmarks for each building. This finding also helps show the importance of the occupant in achieved energy use for a building. By using the iSERVcmb approach to provide a firm basis to understanding the physical Estate, the paper illustrates how operational data from numerous data streams in the Estate can be processed in a number of ways to produce the practical day-to-day information needed to help cost-optimally improve the operation of the Estate as its needs and size evolves. Future work will consider quantified improvements achieved in individual buildings and the actions taken to produce these improvements.

ABSTRACT. The Recast-EPBD required an update of the current (2007/2008) set of CEN-EPB standards. This update work started in 2012 and will result in a new set of 42 CEN-EPB standards.. Where possible this work is be done parallel with ISO. This project is based on EU-Mandate 480. This mandate accepted by CEN, required a really out of the box thinking approach of the standard developers. This project is coordinated by CENTC371 the “Program Committee on EPBD” and is considered to be a step forward in progressing towards European Energy Codes for Buildings. This second generation of EPB standards aims on more comprehensive standards, a clear split between informative text in Technical Reports and normative text in Standards, attached excel files to illustrate the calculation procedures etc.. The EPB set of standards and technical reports will support the holistic approach needed for the Nearly Zero Energy Buildings (nZEB) and high performance energy renovation of the existing building stock. The developed set of EPB standards is considered as the important instrument to support the proper implementation of the EPBD policy in the EU. The developed set of EPB standards is the modularly structured, transparent, unambiguous, but a flexible set of EN and EN/ISO standards. The modular structure of EPB standards is flexible in order to take into account national and regional choices. An approach has been introduced, via the so-called Annex A and B in all EPB standards. Annex B is an informative Annex and includes all default values, choices and options needed to use the standard. Normative Annex A includes empty tables for these needed values, choices and options, this empty template shall be used by National Standard Bodies (NSB) (or recognised local, regional or national authorities) to declare these values, choices and options to be followed under their jurisdiction. This approach allows maximal flexibility and transparency in applying the EPB standards. If published by the NSB’s these Annexes conform Annex A are indicated as National Annexes. The flexible approach included in these EPB standards, sometimes criticised, but allowing maximal freedom in innovative design approaches , able to demonstrate the impact of smart energy infrastructures as expected in future smart communities. Formal Voting drafts of all EPB standards will be ready by April 2016. The formal voting on these standards is expected during September-October 2016. After the EPB standards are accepted the publication by the end of 2016 /beginning 2017 seems possible.

ABSTRACT. The growing interest in the energy performance of buildings brings along questions about the real energy performance of occupied buildings. While building simulations are useful to estimate the building performance during the design phase, these theoretically estimated energy use figures often differ significantly from the real energy use of the occupied building. Reasons for this can be, for example, deficiencies introduced during construction works, the actual operation of the building services as well as occupant behavioural aspects. On the other hand, the increasing application of energy monitoring systems, leads to an increasing availability of frequent (e.g. quarterly or hourly) and long-term measurements of the actual energy use and possibly energy-related parameters in occupied buildings. By use of data-driven modelling techniques, the actual energy use of buildings can be modelled and the model can be used to, for example, normalise the data or identify energy savings.

Heating degree day and energy signature methods are widely applied data-driven energy models, that are typically used when occasional measurements are available over long periods of time. However with the availability of energy monitoring data that are more frequent and long term, the applicability of these classical methods is questioned from statistical point of view, and on the other hand more accurate models and more extensive information are expected from the analysis of these data. Therefore in this paper, various data-driven modelling techniques are applied on a data-set that includes hourly gas, electricity and weather monitoring data for numerous dwellings in Belgium during several years. Steady state linear regression models are applied as a reference, and then dynamic models such as linear input-output models are investigated and compared in terms of statistical quality, accuracy and reliability, for different levels of aggregation and length of the data-set.

ABSTRACT. Acupuncture & moxibustion treatment is a very important therapy method in traditional Chinese medicine, which is widely used in Chinese medicine hospital. However, smoke including fine particles is produced due to combustion of artemisia argyi during acupuncture & moxibustion treatment. It is well known that smoke especially fine particles threat the health. Study are needed to investigate the particle concentration and size distribution in the treat room during acupuncture & moxibustion treatment.

Nine acupuncture & moxibustion treatment rooms in different hospitals in Nanjing were investigated to evaluate the particle levels during acupuncture & moxibustion treatment. The Q-Trak indoor air quality monitor and Aero Trak particle counter were employed to measure particles number concentration, temperature, RH and CO2 and CO concentration during acupuncture& moxibustion treatment in the heating period when the windows are usually closed.

The I/O (indoor particle concentration/outdoor particle concentration) for 3 sizes in 9 treat rooms are all higher than 1. Smaller particle has higher I/O value. I/O ranged 1.18-2.57 for particle with size 0.3-0.5 mm; 1.09-2.13 for particle with size 0.5-5 m and 1.02-1.89 for particle with size 5-20 mm.

Combustion of artemisia argyi during acupuncture & moxibustion will produce large number of particles especially fine particles, which is the most important pollutant source in the treatment room. The controlling methods are needed to reduce particles level in the treatment room.

ABSTRACT. Building energy conservation plays an important role in energy saving and emission reduction, and the efficiency of new residential buildings is likely to be improved under the policy instruction. To increase the building air-tightness and reduce fresh air supply are usually considered as effective means in energy-efficient buildings which are likely to lead to changes in indoor air pollution such as particulate matters (PM). Three typical residential building models were created in the multi-zone airflow and contaminant transport program CONTAM in order to simulate airflow and PM2.5 concentrations in Nanjing dwellings. The airflow path elements considered for each building model included the exterior wall leakage, interior wall leakage, exterior door and window, etc. Both indoor and outdoor source of PM2.5 were considered for indoor PM2.5 concentration comparison and analysis. The results of the simulation and analysis indicated that the concentration of indoor PM2.5 varied among different residences. The tighter the building was, the less influence of outside pollution on indoor PM2.5 concentrations, when the doors and windows were closed. With the presence of indoor pollution sources, indoor concentration of PM2.5 increased rapidly. Increase efficient building ventilation, especially with the presence of indoor sources, was of great significance in improving indoor air quality, reducing the indoor concentration of PM2.5 and its adverse effect on human health.

ABSTRACT. In this case study we measured the indoor air quality and analyzed the performance of ventilation and air conditioning system in school campus where each building has a mechanical ventilation system. The following reviews and studies were made: review of existing documents and maintenance practices, technical review of ventilation systems and air flow measurements, indoor air quality measurements, and walk-through audit of all spaces. An online User Satisfaction Survey was carried out among school staff. Room air particulate levels were too high and therefore air filtration needed to be improved and all buildings needed to be properly over-pressurized. All ventilation system components (including air handling unit rooms) needed to be functional and clean. Target was set to reduce indoor air particulate matter PM2.5 (2.5 µg/m3 and smaller) level to be 70% below ambient air level, to remove traffic emissions (gases) from supply air and improve the cooling in classrooms. Proposed improvements were piloted in one of the buildings. Ambient Air Purifier units were installed into the outdoor air intake. Entire ductwork was cleaned. New filters were installed to air handling units. Ductwork was balanced to ensure positive pressure in all classrooms. After the pilot project the indoor air quality was measured and compared with ambient air measurements. During the first measurement period, ambient air PM2.5 level was 142 µg/m3 and in the classrooms 95% less i.e. 7 µg/m3.

ABSTRACT. Both new and renovated existing buildings will in the future need to be optimized in such a way that can achieve to have nearly no energy use while still providing impeccable indoor climates. Since such buildings can already be assumed to be very well insulated, airtight, and to be equipped with heat recovery systems, one of the next focal points to limiting energy consumption for thermally conditioning the indoor environment will be to possibly reducing the ventilation rate, or to make it in a new way demand controlled. However, this must be done in such a way that it has no adverse effects on indoor air quality (IAQ).

Annex 68, Indoor Air Quality Design and Control in Low Energy Residential Buildings, is a project under IEA’s Energy Conservation in Buildings and Communities Program (EBC), which will endeavor to investigate how future residential buildings are able to have very high energy performance whilst providing comfortable and healthy indoor environments. New paradigms for demand control of ventilation will be investigated, which consider the pollution loads and occupancy in buildings. It will be necessary also to consider the thermal and moisture conditions of such advanced building because of interactions between the hygrothermal parameters, the chemical conditions, ventilation and the wellbeing of occupants.

The project is divided into the following five subtasks: 1. Defining the metrics 2. Pollutant loads in residential buildings 3. Modelling - review, gap analysis and categorization 4. Strategies for design and control of buildings 5. Field measurements and case studies

After setting the baseline of requirements in Subtask 1, the project will gather state of the art knowledge in Subtasks 2 and 3 and identify gaps of knowledge on combined effects between hygrothermal conditions, transportation of pollutants and air flow regimes around materials in indoor environments. The role of materials to act both as sources or sinks of pollutants will be considered.

A flagship outcome of the project is anticipated to come from Subtask 4 in the form of a guidebook on design and operation of ventilation in residential buildings to achieve high IAQ with smallest possible energy consumption.

Subtask 5 will gather field tests and case studies from various climates and residential building typologies represented by the Annex Participants, and document these with regards to performance on good IAQ and low energy use.

The paper will illustrate the working program of each of these activities, and the presentation of the Annex project at the conference shall foster some interest and discussion about its work items.

ABSTRACT. The study presented in this paper is a continuation of Abdelmaksoud and Khalil (2013 and 2015) study on the occupant's thermal comfort in office spaces. That study was performed using the computational fluid dynamics (CFD) method and recommended the use of modern ventilation system that combines the effect of displacement ventilation and personal ventilation systems. This ventilation system provides an ideal thermal comfort for the occupant in the office. The thermal comfort is independent of the indoor air quality, which was not included in Abdelmaksoud and Khalil studies. Poor indoor air quality can induce health problems and lower the activity level. The carbon dioxide (CO2) is used in the present study as an indicator of the air quality in the space. The CO2 is emitted with human’s respiration and correlates with the human metabolic activity. ASHRAE recommends a maximum limit of 700 ppm differential between indoor and outdoor levels of CO2 concentration. In the present paper, we investigated the CO2 concentration distribution around the occupant location in the office cubicle configuration that was presented in the earlier papers of Abdelmaksoud and Khalil (2013 and 2015). The objectives were to: (1) investigate the CO2 concentration level in the breathing zone of the human, and (2) recommend a minimum amount of outdoor air ventilation rate that maintains the CO2 concentration in the breathing zone below the maximum allowable limit. To achieve these objectives, several CFD cases were studied and their results are presented in this paper.

ABSTRACT. This study aims to investigate the level of indoor air pollutants in selected schools for different types of class rooms and level of activities in Singapore. Indoor air quality (IAQ) parameters in five tertiary school buildings were measured during the period between year 2013 and 2014. In each school building, carbon dioxide (CO2), carbon monoxide (CO), operative temperature (OT), relative humidity (RH), respirable suspended particulates (RSPs), total volatile organic compounds (TVOCs), formaldehyde, air velocity, total bacterial count and total fungal count compare the air quality to SS554 Code of Practice for Indoor Air Quality for Air-Conditioned Buildings in Singapore were performed during school hours, and a complete walkthrough survey was completed. The results show that elevated levels of carbon dioxide and bacteria were found in lecture theatres when it is occupied. This could be due to the high occupancy with insufficient ventilation. Introduction of more fresh air and better air circulation can help to alleviate the problem. The OT results at several locations were found to be lower than the recommended range of between 24-26°C. Generally, in a well maintained building, it would be reasonable to maintain the operative temperature at around 24°and 26°C. The goal should be to maintain the temperature that will satisfy at least 80% of the occupants. Air movement in a few indoor locations were found to be lower than the recommended range. This may not have direct influence over occupant’s perception in indoor environment as compared to temperature and humidity. However, it is synergistically related to the thermal comfort and the overall performance of the ventilation system. Too high or low air movement will affect the thermal comfort of individuals. Total bacterial counts at many indoor locations exceeded the recommended threshold limit of 500CFU/m3. Human occupants themselves are normal reservoirs of bacteria; the level of airborne viable bacteria is based on the number of occupants and their activity at the site. Bacterial impurities found in the indoor environment should normally be removed through the ventilation systems and cleaning procedures. Improving the ventilation system and routine cleaning or regular house-keeping should lead to lower level of airborne bacteria.

ABSTRACT. The object of this paper was to find a relationship between Indoor Air Quality (IAQ) and Airside economizer. All outdoor air come to space, when airside economizer is operated. However, if outdoor air quality exceeds IAQ standards, occupants feel uncomfortable and even get disease of respiratory or heart. This paper supposes a method that reduces contaminants coming to space when airside economizer was operated. The main idea was to adopt Air Quality Index (AQI) as a constraint. For reference, AQI was determined by most adverse influence factors to air quality among PM10, PM2.5, Ozone, Nitrogen dioxide, Sulfur dioxide. Level of AQI from zero to fifty is good state and from fifty-one to one hundred is moderate state. For example, If AQI exceeds certain level harming to human, airside economizer stops operation although outdoor air has good condition for airside economizer. Simulation was developed using ENERGYPLUS, OPENSTUDIO and Commercial equation solver (EES) programs. This study selected the several big cities in South Korea, China, Japan and USA. Simulation results from Shanghai showed PM2.5 concentration over 75㎍/㎥(China’s PM2.5 standards) was 1190hours/year when differential enthalpy based economizer. However, that was 1007hours/year after differential enthalpy based economizer restricted AQI. Chiller energy consumption increased 0.47% in differential enthalpy based economizer restricted AQI than differential enthalpy based economizer. it was found that PM2.5 concentration over 75㎍/㎥ period was reduced 15% amount of period when differential enthalpy based economizer restricted AQI.

ABSTRACT. Any historically significant interior require special attention in connection with indoor air quality control, especially hydro – thermal microclimate is essential. Air temperature and relative humidity, and in particular their sudden fluctuation over the time, have a wide implication for preservation. Unfortunately, in many historical interiors these parameters lie far beyond the tolerated range. In this case it is necessary to carry out measures leading to improvement conditions and the same time take into account economic aspect and the request for more and more decreasing energy consumption. Any intervention or restoration action should be preceded by a thorough analysis of current situation. This statement applies to all building, but for historical objects this is especially true. In order to proper determinate of initial conditions, monitoring in appropriate time period has to be done. This paper presents a study performed on the Pilgrimage Chapel of Holy Stairs in Rumburk, Czech Republic, that proposes the use indicator of preservation risk as a tool for indoor environmental assessment. Monitoring data, which are basis of examining initial condition in the Chapel, allows a calibration of numerical simplified model in the software Design Builder GUI with calculation core Energy+. The 3D model assesses improvement of indoor environmental quality in the chapel depending on various measures leading to better condition and the building plant system characteristic. One of the main issues of the analysis is compare the relationship between level of quality of the internal microclimate and requirements for potential HVAC systems.

ABSTRACT. INTRODUCTION Achieving a satisfactory indoor air quality in buildings requires control of the relative humidity of indoor environments. Maintaining proper moisture conditions inside buildings it is determined by the hygroscopic balance in interiors. The ability of coating materials to buffer relative humidity fluctuations is called Moisture Buffer Value (MBV) and it can play a key role in the hygroscopic balance. Two variables that have great influence when assessing MBV of a material are the mass transfer resistance value of the vapor film surface layer and the sample width. The last has to be, as minimum, equal to the moisture penetration depth of the material. Besides, it is not so clearly defined the influence of the exposed surface of the samples during testing. In this work the influence of the size of the testing sample is studied and its impact on the MBV results is evaluated. Samples of different size are evaluated by dynamic tests in a climatic chamber. The testing material is lightweight ceramic clay, widely used in buildings energetically efficient for its high thermal performance and hygroscopic character. It is concluded that the size of the specimens is critical not only in the accuracy of results, but in the interpretation of the hygroscopic behavior thereof. METHODS Tests were carried out according to NORDTEST protocol. The samples were exposed to repeated step changes on relative humidity between 75%RH during 8hours and 33%RH during 16hours. The temperature was kept constant at 23ºC. The samples weight changed according to the periodic relative humidity changes. The changes of weight were normalized per exposed surface and RH change, in order to obtain the MBV of the material. The NORDTEST protocol sets the sample minimum exposed area in 0,01m2. In this research two samples sizes were used; one was according to the NORDTEST protocol and the others (33*95*6 mm) were smaller than the required by the protocol, in order to compare the results. RESULTS Tests with different sample sizes provided contradictory results. The results with smaller samples showed that weight increased when the relative humidity decreased, and the weight decreased when the relative humidity increased. The result was exactly the opposite than should be expected according to moisture transfer principles. The weight for samples with minimum sizes according to the Nordtest protocol decreased when the relative humidity decreased, and increased when the relative humidity increased. These results were the expected. CONCLUSIONS The most important conclusion is about the importance of the required minimum size for the testing sample. It is important not only for the accuracy of the test results but also for the correct reproduction of the physical phenomenon involved. Not using samples with the minimum area required means less hygroscopic inertia but also a lower coefficient of mass transfer resulting in a combined effect of both parameters that may be inconsistent with the phenomenon to be played. Consequently, it is critical selecting a correct sample size when measuring the Moisture Buffer Value, in order to reproduce the buffering phenomenon that occurs in buildings indoor environment.

ABSTRACT. Schools change, they become more sustainable but also their functional structure changes. More and more activities are no longer done in classrooms but in shared working places in a kind of courtyards. Indoor air quality and thermal comfort in traditional existing schools are now almost universally worse than the relevant standards and building codes stipulate that they should be. The Dutch government therefore proposed a concept, named fresh school literally translated from Dutch, frisse scholen, to assure children’s health in school. This paper presents the field measurements that investigated indoor air quality and thermal comfort of four recently built fresh schools with shared working areas between classrooms, in urban and rural areas in the Netherland during the heating season. CO2 concentrations were measured in four learning squares for seven days, continually. The results have shown that learning squares in these newly built primary schools have very good IAQ and satisfying thermal comfort during heating period, mean value of CO2 concentration at breathing zone to below 800 ppm during 95% of weekly school time. It would seem that the basic requirement of 800 ppm of CO2 is achieved as a consequence of the installed balanced ventilation system being just sufficient to provide ventilation rate at fluctuated and intermittent occupancy. Thermal comfort in the monitored rooms was mostly satisfying, and temperatures tended to be fluctuated around 21°C and the relative humidity ranges from 30% to 60%, as the design assumed. The most significant conclusion is that the four learning squares in primary schools achieved satisfying results during measuring period, which differs from the previous studies.

ABSTRACT. INTRODUCTION Ventilation systems have been installed in all houses in Japan since the amendment of building standard toward the sick house problem in 2003. However ventilation systems are not used continuously in most houses. The reasons are thought to be energy saving, the noise of ventilation systems, the lack of understanding on indoor air quality, etc. After the Great East Japan Earthquake, saving electric energy is required and portable stoves using kerosene are used in many houses. Therefore it is also required to give correct information about indoor air quality to every dweller. In this study, the way of using a ventilation system is investigated using the survey results on mold, mite and environmental factors in houses in 2006. And the risks of lowering indoor air quality were calculated using a simulation program “Fresh”. The annual changes of indoor air quality are calculated in houses with some risk factors: the intermittent usage of ventilation systems, the usage of kerosene stoves and the emission of chemical compound from building materials, etc.

METHODS The state of ventilation in houses is investigated using a national survey on mold and mite. The influences of building factors and living styles upon the rate of using ventilation systems is analyzed using a statistical method. And annual indoor air quality is calculated in some typical models of houses with risk factors using a simulation program ”Fresh”. The temperatures, humidity, concentrations of carbon dioxide, carbon monoxide and chemical compounds, and energy consumption are calculated considering the building performances and dwellers’ behaviors in houses.

RESULTS and DISCUSSION The rate of houses continuously ventilated is 30% in the case of exhaust ventilation systems and 60% in the case of exhaust and supply ventilation systems in winter. The rates in summer are 25% and 80% in each case. The ventilation systems are not used continuously in many houses. The ventilation systems are used temporally to control indoor comfort. Sometimes dwellers use their ventilation system to exhaust pollutants from their kerosene stove in winter and sometimes to make rooms dry in summer. In the case of exhaust ventilation systems, dwellers use both ventilation systems and windows in winter. The simulation results showed that indoor air quality depends on dweller’s behavior especially in airtight houses with exhaust and supply ventilation systems. If kerosene stoves are used in these houses, the indoor air quality is not acceptable to the dwellers. The simulation results showed that giving information about indoor air quality is very important for dwellers as well as home builders.

ABSTRACT. Recently condensation and mold problems have been reported frequently in modern residential buildings with air-tightened and insulated compared to the traditional housing in Korea. The condensation in residential buildings can be solved by controlling the humidity level or surface temperature. The purpose of this study is to develop the ventilation system to prevent condensation in residential building. In this study, the water vapor generation rates were measured by field measurement considering the life style and building conditions of Korean households. Field measurements were conducted in 148.5m2 of the residential building. Relative humidity and temperature were recorded to analyze the water vapor generation rate by various household activities. Shower, bathing, cooking, drying laundry were specified as moisture generating activities in Korean households. Indoor moisture generation rates were calculated from the measured relative humidity data. The moisture generation rate was 358.1g/h, 153.2g/h, respectively in case of the shower and bath. The moisture generation rate was about 567.8g/h in cooking, and about 173.6g/h in laundry drying. The moisture generation rates suggested in this study were somewhat lower than those of the previous studies. However this results reflects the Korean life-style and residential building characteristics.

ABSTRACT. The basic regulation formula (RF) based on direct-connection DH system is widely used to operate the DH systems, but the formula maybe not suitable for indirect-connection DH system. Here indirect connection means that the working fluid circulated in CHP and the primary network is not the same medium that flows in the secondary network. Therefore, this paper deduces the regulation formula for indirect-connection DH system. According to accuracy analysis, we find that the applicability of the regulation formula should be based on three conditions: 1) The design indoor temperature and volume specific heat load of all buildings are the same; 2) The same type of heating devices are used in the buildings after each substation or all heating devices are deemed as a big radiator with average performance; 3) The supply and return water temperatures in primary and secondary sides are the same for each substation. If the three conditions cannot hold true at the same time, then the accuracy of regulation formula should be analyzed first.

ABSTRACT. The competitiveness of traditional district heating systems against autonomous heat supply solutions is going to decrease in the next decades due to the expected negative trend of heat demand. This problem is addressed by low temperature district heating systems –i.e. networks with supply temperature of about 55°C- that are capable of abating distribution heat losses and increasing efficiency of supply plants. Here, a new concept of district heating system is proposed, where water is circulated at lower temperature – below 40°C – and the necessary temperature gain is provided close to the final users by means of customized water to water heat pumps, so that new low-energy buildings and old poorly-insulated buildings can be supplied efficiently at the same time.

The study considers a real residential neighbourhood consisting of 98 buildings of different age classes, located in Abano Terme (Padova, Italy). In this location, hotels and thermal spas extract almost 8 million cubic meters thermal groundwater per year and then discharge it to the environment at a temperature in the range 35-55°C. The use of this "geothermal wastewater" as heat source to the neighbourhood through a low temperature district heating network with booster heat pumps is investigated. Numerical simulations have been carried out to evaluate the performance of three district heating system configurations: (a) a centralized solution (a heat pump with its auxiliary gas boiler for the whole network), (b) a distributed solution (a heat pump for each consumer) and (c) a clustered solution. The latter comes from the aggregation of dwellings that can be supplied by hot water at the same temperature (as low as possible) without incurring thermal discomfort issues. The heat demand profile of the district has been obtained by a dynamic model based on the 5R1C model of ISO 13790. The inputs to the model are buildings geometry and orientation (imported by a GIS software) and weather data. The district heating network has been simulated with a steady-state one-dimensional model based on graph theory. Both models were implemented in the MATLAB/Simulink environment. The COP used for booster heat pumps comes from measurements on a real prototype specifically designed and built for this purpose in laboratory. The performance of the proposed district energy systems is evaluated in terms of both primary energy saving and reduction in CO2 emissions over the current status (individual gas boilers).

First results confirm that a significant reduction in both primary energy consumption and CO2 emissions can be met by using the geothermal wastewater as a heat source for the district heating network. Moreover, a significant reduction in heat loss can be pursued by transporting heat at low temperature and using distributed or cluster heat pumps, compared to a traditional district heating system. Thus, low temperature district heating networks with booster heat pumps seem to be a promising solution for an efficient use of distributed low grade heat sources in the urban environment.

ABSTRACT. 1.Introduction As a consequence of the transposition of the European Directive 2009/28/CE, the Italian regulation on energy efficiency will require, from January 2017, that thermal energy plants for new buildings or for buildings subjected to a deep renovation, will have to be designed and built to ensure that at least 50% of the heat demand for domestic hot water, heating and cooling will be met by renewable sources. This target could be particularly ambitious, especially in areas with high population density, where the installation of technologies to produce the required heat demand from renewable sources might be difficult due to lack of space or for integration problems. These difficulties could drive designers to invoke the presence of technical constraints. District Heating Systems (DHS) connected to distributed solar collectors could contribute in reaching this target, and especially in urban and densely built areas, could contribute to solve the possible technical constraints: the DHS can act as a virtual storage for the thermal energy produced and not immediately used, with the possibility to use it later and/or to share the renewable source production with the whole thermal network. 2.Methods The Technical Unit for Energy Efficiency of ENEA is developing a software platform in order to design and to perform dynamic simulations of an energy district, where a multi-building system (residential buildings, dwellings, office buildings, shopping centers, etc.), with inhomogeneous electric and heat loads, is served by advanced electric and thermal networks. A recent development of the platform allows to investigate the presence of customers, connected to a DHS, that not only can consume but also produce district heating by means of small-scale solar collectors. A small-scale district heating system located in a suburb in the Municipality of Bologna (Italy) and including residential buildings, schools, public buildings and a commercial building and heated by gas boilers was simulated. The introduction, in the simulated DHS, of one or more solar thermal fields integrated on the roofs of the buildings was studied, and sensitivity analysis on the effect of the number and the size of the solar fields on the energy and economic performance of the DHS was carried out. 3.Results, Discussion and Conclusions The energy performance of the DHS integrated with the solar fields reach its optimum in the configuration that maximize the local self consumption of the produced solar energy. Using the DHS as a vector to share the heat produced by solar energy, the increase in the thermal losses of the DHS can be considered acceptable in the configurations with a solar production equal to or lower than the domestic heat water loads plus the heat losses of the whole DHS in summer. The economic performance of the introduction of solar thermal, can be considered acceptable only for the configurations with a lower number of installed solar fields.

ABSTRACT. The reduction of system temperatures in district heating networks increases the potential for renewable energies and industrial waste heat, reduces heat losses, increases the capacity of the heating network as well as enables a higher efficiency of many conventional heat generators. In this paper a methodology for assessing local temperature reduction potential in district heating networks by demand side measures (thermal retrofitting) and cascading solutions is described. For the case study of Klagenfurt the local return temperature reduction potentials have been evaluated, achieved by thermal retrofitting of the building envelope according to OIB RL 6 and in turn reduced temperature demand for space heating. Exemplary, “business-as-usual” (BaU) and more ambitious retrofitting scenarios have been identified, modelled and simulation results allowed the evaluation of the impact on the return temperature reduction and heat distribution losses in every pipe at city scale. The simulation results of the BaU scenario showed only a very limited impact with about 0.3 K weighted average network return temperature reduction and a decrease of about 5 MWh heat distribution losses. The “very ambitious” retrofitting scenario results in a reduction of about 1.2 K and 21 MWh heat distribution losses decrease. However, it can be seen that, due to the distribution of the different building types and structures throughout the city, the return temperature reduction in the pipes varies significantly, represented in a standard deviation of 4.1 K for the BaU scenario and 4.6 K for the “very ambitious” scenario.

ABSTRACT. This study belongs to a wider research project that aims to assess solar irradiance potential at urban scale, in which technologies to convert solar energy into thermal or electrical energy are evaluated. In particular, the annual efficiency, energy output and their sensitivity to dwelling characteristics are required. Although experimental measurements are the most accurate way to determine these efficiencies, it can be a time and a resource consuming process. On the other hand, simulation models allow to predict the systems performance in less time than experimental testing, not only under diverse operating and climatic conditions but also with different dwelling characteristics. However, the accuracy of these models must be validated through short-term experimental data. This leads to the following three sections of the present study: test bench experimental characterization, systems modelling and annual simulation.

Two systems with different collectors are analysed, the first system has a flat plate thermal collector and the second one has an hybrid PV-T collector. Both are indirect circuit systems with forced circulation and a storage tank with a mantle heat exchanger.

Both systems are built up on a test bench, by measuring temperatures at the inlet and outlet of collector and storage tank, incident irradiance at the collector plane as well as primary and secondary flow rate. Daily test are carried out under normal operating conditions, first separately for each system component and finally for the system as a whole.

The systems are simulated in TRNSYS, with models validated through the experiments described previously, in order to correlate their efficiencies with dwelling parameters such as collecting area, roof orientation, number of inhabitants, hourly distribution of DHW demand, and the ratio between storage volume and collecting area. As study case it is used a dwelling located in Concepción, Chile.

From the experimental validation, it is obtained that the daily collector efficiency mean error is less than 2%, meanwhile the error of the heat delivered to the water inside the tank is 6.8% and it is produced, mainly, due to the mixing of water inside the tank during the draw off, also, the daily thermal efficiency mean error of both systems is less than 4%. As result from the study case for an annual simulation, the flat plate collector system efficiency is 45%, while the electrical and thermal efficiencies from the PV-T system reaches 8.3% and 31%, respectively. From the parametric analysis it is extracted that the annual efficiency of the systems is mainly sensitive to the number of inhabitants and number of collectors, varying about a 6% and 3% for each parameter in the PV-T system and about a 7% for both in the flat plate collector system.

A good agreement is obtained between the numerical and experimental results, the collector model gives precise results about its efficiency and the storage tank model predicts results that can be used to estimate the energy delivered by the system. Finally, it is concluded that the annual efficiency of SDHW systems mainly depends on number of inhabitants and collecting area.

ABSTRACT. Introduction: Increasing internal loads and outdoor temperatures raise the need for comfort cooling, in particular in office buildings. Free-cooling methods are applied as energy-efficient cooling in office buildings. A method presently hardly considered is the heat rejection by activated components of the building envelope. An even more advantageous operation is the heating and cooling operation with the same building envelope component. However, requirements for the surface properties may be different for the single operation modes, resulting in optimisation potential depending on the prevailing load situation. The project aims to characterise the surface properties regarding performance in different operation modes as well as operation limits.

Methods: Solar absorbers with different properties have been lab-tested to characterise the capacity for both space heating and cooling application. Based on the lab-tests, an absorber model is set-up and validated. Subsequently, the absorber model is integrated in a system configuration suited for multifunctional operation consisting of a source storage, a heat pump and TABS as emission system in the room zones. Coupled building and system simulations are performed to evaluate key figures of the system performance in different operation modes.

Results and Discussion: In space heating mode capacities up to 550 W/m2 are reached with good solar irradiation and selective coating of the absorber. At low radiation, the outer surface can be operated as outdoor heat exchanger to the ambient air. On the other hand, cooling capacity ranges from 70 W/m2 (selective) to 150 W/m2 (non-selective) in clear sky nights of a normal summer based on weather data of Zurich Meteoschweiz. Regarding space heating operation in winter solar fractions of about 75-80% are reached as solar heat source corresponding to an overall SPF of 4-5 for the heat pump operation and direct solar heating. On the other hand, about 90% of the summer cooling demand can be covered in free-cooling operation by nighttime heat rejection to the ambience and radiation to the sky. Selective properties of the surface are less important as source energy for space heating with the heat pump and for cooling in moderate nights. However, non-selective properties are important for radiation to the sky in hot summer nights and selective coating enables increase of performance by direct solar heating.

Conclusions: High renewables fractions and efficiency in both space heating and cooling mode can be reached with moderate heating and cooling loads in modern office buildings applying outer building surfaces as heat source and sink, respectively. System technology should therefore be adapted to enable multifunctional operation in both operation modes. Optimisation of the surface properties to the prevailing load situation can increase the performance. The technology is suited for medium-sized, low-rise office buildings due the limitations of building surface for high-rise buildings.

ABSTRACT. This paper describes the modeling and dynamic simulation stages of a meeting room of a real building in İzmir chosen as a thermal zone. Modelling part is detailed as possible as it can be to represent the real world behaviour of room including the internal heat gain, infiltration, ventilation and heat losses from building envelope. The thermal zone is cooled using solar aided air conditioner which takes its energy either from PV Panel/Battery system or grid but not both at the same time. In this study, we show how to model thermal zone, PV Panel/Battery system in MATLAB/Simulink. Then we simulate our system consisting of thermal zone, PV Panel/ Battery system and grid using the real meteorological values of İzmir through the years 2008 and 2012 summers. We run the simulation for different sizing of PV Panel/Battery system, and then compare and report the share of renewables. We also discuss the optimal sizing of the battery capacity to avoid frequent on and off states which reduces the lifetime of the battery. This study is part of a wider project whose final purpose is to control the performances of the system components in various climate conditions, maximize the energy production, design and size the components of the system in an optimal way.

ABSTRACT. According to the increasing energy concerns in the world, many researchers have focused on the application of renewable energy in building a net zero-energy building (ZEB). Every residential and commercial building needs to reduce its energy requirements by improving the energy efficiency within the building itself and also by balancing its energy supply needs with renewable energy technologies. To reduce energy, the photovoltaic system (PV system) in particular has recently come to be widely used in buildings despite their geological requirements due to adjacent natural and man-made features. There are many ways to install PV systems in a building. For existing buildings, the PV modules are mounted above and parallel to the roof surface with a standing frame. In a new building development, in addition to mounting the system on the roof top, the PV system could be installed in a creative, aesthetically pleasing manner via integration into the building façade. This type of PV system is commonly known as a Building Integrated Photovoltaic System (BIPV system). This system could be placed on any part of the roof or external wall claddings, windows, or external shading devices. Louver-type BIPV systems can be used not only for electric power generation but also for daylight control. For the application of the louver-type BIPV system, it is necessary to anticipate the performance parameters to increase the electric power generation efficiency without any loss of daylighting performance. Generally, the PV modules should be installed in places that are not shaded by adjacent obstacles. Shading may reduce the electric power output of the entire module drastically. Therefore, shadows cast by the adjacent tall trees and neighboring buildings (including those to be built in future) should first be evaluated. This study aims at evaluating the daily electric power generation efficiency of louver-type BIPV system in urban buildings and determining the performance parameters that affect the power generation efficiency. For this purpose, we have installed the louver-type BIPV system on the south façade of a campus building in Seoul and measured the electric power generation rate and incident solar radiation since May 1, 2013. By analyzing annual field measurement results, electric power generation efficiencies were calculated and analyzed according to the solar position and the location of adjacent buildings. The results show that the annual average power generation efficiency of the PV system is approximately 4 %, which is very low compared to the general case of mono-crystalline solar cells. This low efficiency occurred because of a decrease in incident solar radiations to the PV system due to the seasons, the adjacent building, and self-shading and dust on the surface. We have specifically evaluated the effect of the adjacent building on the electric power generation efficiency by comparing the electric power generation efficiency of the PV system before and after the adjacent building construction processes. We can anticipate that the power generation rate can be decreased significantly due to the adjacent buildings in an urban area.

ABSTRACT. In recent years, the application of the building-integrated photovoltaic-thermal (BIPVT) technology has developed rapidly around the world. The BIPVT module can generate electricity and hot water simultaneously. These features can effectively reduce the fossil fuel energy consumption in the building sector. In this paper, a dynamitic simulation model is developed to evaluate the energy performance of the single-glazed flat-plate-tube BIPVT module. The impact of configuration parameters of the BIPVT module has been analysed. Based on the investigations, the optimum design of the BIPVT module is obtained. For the optimum design of the BIPVT module, the average electrical efficiency and average thermal efficiency is respectively 12.9% and 46.9%, increasing by 4.0% and 9.6%, compared with the initial design.

ABSTRACT. The power generation of photovoltaic systems is significantly influenced by external/internal loss factors. Therefore, the design process of photovoltaic systems requires the information of performance characteristics under various environmental conditions to estimate real power generation. This research deals with the characteristics of power losses in photovoltaic module under different partial shading and solar irradiance that cause abnormal responses of voltage-current. To analyze the effect of each loss factor, several test scenarios were tested in a laboratory. As result, reduction in power generation was affected more by circuit configurations(parallel, bypass diode) than shading patterns(shading location, ratio). Also, the performance of the entire module was proportional to the solar intensity. The analysis of this experiment can be applied to improving the accuracy of performance estimation when designing photovoltaic systems and mathematical models.

ABSTRACT. Over the last several decades, many low energy technologies have been developed and deployed to reduce building energy consumption. Among various solutions, solar photovoltaic thermal (PVT) collectors and phase change materials (PCMs) are among the most promising methods receiving increasing attention. This paper presents a thermal performance evaluation and optimal design of buildings integrated with air-based solar PVT collectors and PCMs embedded in the building envelope by using The Hooke-Jeeves pattern search method. The Hooke-Jeeves generalized pattern search is used to search for optimal solutions of the optimization problem. The variables optimized include the PVT air flow rate, additional wall insulation and PCM layer thickness. The optimal values identified by using the Hooke-Jeeves pattern search method for the PVT air flow rate, additional wall insulation and PCM layer thickness were 1359.4 kg/h, 3.0 m2·K/W and 0.03 m, respectively. The Coefficient of Thermal Performance Enhancement (CTPE) of the house reached 72.6% when the optimal design values identified were used.

ABSTRACT. Considering the increase in energy production and consumption of Turkey in the last decade, energy consumption in 2000 which was 81.193BTEP has increased to 120.290 BTEP in 2013. The rate of meeting consumption through production is 26.5%, thus rest of the consumption which is 73.5% is met through imports. This situation indicates that substantial amount of national revenues of the country are spent on energy imports. When this situation is investigated in terms of electric consumption in parallel with technologic advancement and economic growth, 128.295GWh consumption in 2000 increased to 246.352.GWh in 2013. The Turkish Building Sector (TBS) includes space heating, water heating, cooking and electrical appliances for energy consumption. In the following subsections, the utilization of energy and exergy in the TBS in the years of 2013 is analyzed. The specific applications for energy and exergy consumptions were determined for 2013. In 2000, of Turkey’s end use energy, 33% was used by the residential sector. Share of the energy utilization in the residential-commercial modes is as follows: space heating with 42%, water heating with 30%, cooking with d 12% and electrical appliances with 17% in studied year. These values are determined for 2013. Energy and exergy utilization values determined for the year studied in the TBS. The highest contributions came from renewable resources (includes wood) with 41.50,%, fuel with 38.70 and electric with 19.80 in the 2013. In 2013, the highest contributions came from wood with 212.40 pJ. In this case, the result of development of economic in studied country. However, natural gas usage has continuously increased in the TBS for space heating, water heating and cooking purposes in several cities. Natural gas constituted 103.73 pJ of used energy in this sector in 2000 and is projected to account for 453.68 pJ of that in 2013. In addition, utilization of renewable energy is spread in the TRCS, especially from sunlight for water heating, from geothermal for water heating and space heating and from bio waste for general usage. Turkey has substantial renewable energy potential. Renewables make the second- largest contribution to domestic energy production and consumption after coal. However commercial use of renewable energy in Turkey, excluding large-scale hydropower, has not developed in proportion to its large resource base. Renewable energy use has been dominated by large hydro and biomass (mostly wood and animal wastes). The huge potential of Turkey in renewables like wind, solar, and geothermal has not been used efficiently until recently. Unfortunately, the use of new renewables (renewables excluding large hydro) is therefore still extremely limited because of low growth. Although the absolute value of renewable energy use grows, its share of the Total Primary Energy Supply does not increase since it doesn’t grow in proportion with energy consumption. So, the share of fossil fuels continues to increase, especially natural gas. Renewable energy plays a critical role to satisfy rising energy demands and to achieve low-carbon economy. Renewable energy policy has become a focus of national policy formulation and legislation.